JPWO2006109462A1 - Wireless communication system and wireless communication method - Google Patents

Abstract

The terminal (101) includes an interface for communicating with the mobile network (102) and the wireless LAN network (103). The first IMS server (107) performs IMS call control processing relating to terminals existing in the mobile network (102), and the second IMS server (111) performs IMS call control processing relating to terminals existing in the wireless LAN network (103). It relays the signal regarding. These IMS servers search for a mobile network packet relay device (106), a packet data relay device (110), and a relay device to be controlled by a path switching request for requesting switching of a packet transmission path, and perform path switching. Relay the request. Then, the path switching request from the terminal (101) is relayed by the IMS server, the switching request is output to all the networks to be specified, and the packet transmission path is switched by the relay apparatus according to the request. Thereby, a terminal having both mobile communication and wireless LAN interfaces can select a network to be used for each communication port.

Description

  The present invention relates to a wireless communication system capable of optimally distributing communication of a terminal having a mobile communication and wireless LAN interface to both communication networks in a cooperative system of a mobile communication network and a wireless LAN network. It is about technology.

  In recent years, the construction of a communication system in which a cellular phone capable of communicating in a wide area and a public wireless LAN service capable of high-speed data communication in a relatively small area are linked (interworked) to complement each other has been studied. In such a communication system, for example, a terminal that can access both a mobile communication network of a mobile phone and a wireless LAN is used, and connection is made using a mobile network having a wide coverage area per base station during high-speed movement. On the other hand, it is possible to provide services such as high-speed access using a wireless LAN when moving at low speed or at rest.

  Interworking system is a 3GPP (3rd Generation Partnership Project), a new international standard for creating, distributing, and playing back multimedia over a third-generation high-speed wireless network. Scenario for accessing packet service of mobile network via WLAN The architecture that realizes is standardized. In the 3GPP standard, TR (Technical Report) 22.934 (TS) refers to Technical Specification (TS) 23.234 (3GPP TS 23.234, “3GPP system to Wireless Local Network (S)). Describes the architecture and TS33.234 describes the authentication method.

  In these interwork system specifications, six scenarios from scenario 1 to 6 are defined depending on the form of interworking. For example, in scenario 3, a service that allows a terminal in a wireless LAN area to access a mobile network is defined. Scenario 4 defines a service that allows a terminal communication session to continue when the area of the wireless LAN and the mobile network changes during communication.

  As a method of realizing Scenario 4 with existing technology, Mobile IPv6 specified in RFC3344 (IETF RFC3344, "IP Mobility Support for IPv4") of IETF (Internet Engineering Task Force) and 3GPP standardized. A method of combining interworking systems is mentioned. The aim of this technology is to use Mobile IPv6 to conceal the movement of its own terminal from the communication partner's terminal, thereby continuing the communication session when moving between the wireless LAN network and the mobile communication network. It is in.

  FIG. 19 is a diagram for explaining an outline of a system configuration in which Mobile IPv6 and 3GPP interworking systems are combined. In FIG. 19, reference numeral 1901 denotes a terminal corresponding to a UE (User Equipment) in 3GPP. This terminal 1901 has an interface between a wireless LAN and a mobile phone, and is connected to a mobile (communication) network 1902 and a wireless LAN network 1903. The mobile network 1902 includes a mobile access network 1904, a packet control device 1905, and a mobile network packet relay device 1906. The wireless LAN network 1903 includes a WLAN access network 1908, a WLAN relay device, and a packet data relay device 1910. ing.

  A mobile access network 1904 provided in the mobile network 1902 can communicate with the mobile phone of the terminal 1901 and corresponds to a 3GPP UTRAN (Universal Terrestrial Radio Access Network). The packet control device 1905 performs GPRS (General Packet Radio Service) connection setting of the terminal 1901 and corresponds to a 3GPP SGSN (Serving GPRS Support Node). The mobile network packet relay apparatus 1906 corresponds to a 3GPP GGSN (Gateway GPRS Support Node), and relays packets between the mobile network 1902 and the public packet network 1911.

  The WLAN access network 1908 provides a wireless LAN connection to the terminal 1901 and corresponds to a 3GPP WLAN AN (Access Network). The WLAN relay device 1909 is connected to the WLAN access network 1908 and relays packets that can access the mobile network 1902. The packet data relay device 1910 relays the WLAN packet to the public packet network 1911. The public packet network 1911 is a communication network connected to the mobile network 1902 and the wireless LAN network 1903 and exchanging packets in the public, and corresponds to a 3GPP PDN.

  An IMS server 1907 that connects the mobile network packet relay apparatus 1906 and the packet data relay apparatus 1910 controls the IMS (IP Multimedia Core Network System) that supports real-time communication on a packet, etc., and 3GPP P-CSCF (Proxy) -Call Session Control Function). The user information storage device 1912 manages the connection status of the terminal 1901 and the like. This user information storage device 1912 is connected to the authentication system 1913. The authentication system 1913 relays an authentication signal with the user information storage device 1912 when performing authentication from the wireless LAN. The user information storage device 1912 corresponds to both AAA Proxy / AAA Server of 3GPP.

  A home agent 1914 and a counter node 1915 are connected to the public packet network 1911. The home agent 1914 is a Mobile IP home agent, and the opposite node 1915 communicates with the terminal 1901.

  Hereinafter, an outline of the operation of the communication system shown in FIG. 19 will be described. When the terminal 1901 is powered on, the terminal 1901 first registers its own location and enters a standby state. At this time, the terminal 1901 acquires an access IP address for accessing the mobile network 1902, and registers the terminal 1901 and the mobile IP home IP address in the IMS server 1907.

  The access IP address IPa is an IP address used when the terminal 1901 is connected to the public packet network 1911. When the terminal 1901 uses the mobile network 1902, the access IP address is acquired via the mobile network packet relay device 1906. When the terminal 1901 uses the wireless LAN network 1903, the access IP address is acquired via the packet data relay device 1910. To do. In the example shown in FIG. 19, since the terminal 1901 is located in the area (M1) of the mobile network 1902, the access IP address IPa is acquired from the mobile network packet relay apparatus 1906.

  After acquiring the access IP address, the terminal 1901 performs location registration with the home agent 1914 using the access IP address IPa and the home IP address IPc. As a location registration method in this case, any of a method in which the terminal 1901 has a unique home IP address IPc and a method in which a functional element on the network side assigns the home IP address IPc may be used. After the location registration is completed, the terminal 1901 registers the ID (IMSI, International Mobile Subscriber Identifier) and the home IP address IPc of the terminal 1901 with the IMS server 1907. The above is the location registration process.

  When the location registration is completed, the terminal 1901 starts waiting for a call. Here, an example will be described in which after the standby start, the terminal 1901 makes a call by IMS and starts a videophone call combining voice and video. At this time, the audio and moving image streams pass through the home agent 1914 and the mobile network packet relay device 1906.

  When the terminal 1901 enters the wireless LAN area (L 1), packet transmission is performed to the terminal 1901 via the wireless LAN network 1903. Below, the outline | summary of the hand-over process which performs this switching is demonstrated. When the terminal 1901 enters the cell L1, the terminal 1901 obtains the access IP address IPb of the wireless LAN network 1903. Thereafter, the terminal 1901 performs Mobile IP registration with the home agent 1914 in order to communicate via the wireless LAN network 1903. The home agent 1914 changes the information related to the communication of the terminal 1901 so that the packet transmission path is via the packet data relay device 1910.

  When the above processing is performed, even if the terminal 1901 moves from the mobile network (M1) to the wireless LAN network (L1) during communication, the home IP address IPc used by the home agent 1914 when viewed from the opposite node 1915 changes. do not do. Further, since the home IP address IPc is registered, re-registration with the IMS server 1907 becomes unnecessary.

  Japanese Unexamined Patent Application Publication No. 2004-180311 discloses a method in a wireless communication network for connecting a terminal device and a router. This method uses the first network interface to establish a link layer connection with the first connection point, and then detects the second connection point using the second network interface, The connection point and the link layer connection are established, the compatibility between the connection router connected to the second connection point and the terminal device is determined, and the terminal device and the connection router are connected.

  FIG. 20 is a conceptual diagram for explaining the method disclosed in Japanese Patent Application Laid-Open No. 2004-180311. In the system shown in FIG. 20, the mobile network 2002 and the wireless LAN network 2003 are linked in the same way as the system shown in FIG. A mobile network packet relay device 2004 is disposed in the mobile network 2002, and an LMA 2005 is disposed in the wireless LAN network 2003. Note that wireless-related functional elements such as a radio network controller (RNC) are not shown. The basic operations of the terminal 2001, the mobile network 2002, and the wireless LAN network 2003 shown in FIG. 20 are the same as those of the system of FIG. 19, and the public packet network 2007 and the opposite node 2008 are also connected to the public packet network 1901 of FIG. Since it is the same as that of the node 1915, redundant description is omitted.

  Similar to the mobile network packet relay device 1906 illustrated in FIG. 19, the mobile network packet relay device 2004 relays packets and manages the connection of the terminal 2001. LMA 2005 (LMA is an abbreviation of Local Mobility Agent) relays packets between the mobile network 2002 and the wireless LAN network 2003, and assigns an access IP address according to a request from the terminal 2001. ISP 2006 (ISP stands for Internet Service Provider) provides connection to the public packet network 2007 and assigns an IP address to the terminal 2001.

  In the system shown in FIG. 20, when the terminal 2001 is turned on, the connection of the terminal 2001 to the public packet network 2007 is established. The terminal 2001 acquires an IP address IP-mt by using the GPRS procedure, and creates connection information called “Secondary PDP context” for the GGSN. This “Secondary PDP context” is GPRS connection information such as QoS, but relay information and the like can also be used for a wireless LAN.

  Next, when the terminal 2001 enters the area of the wireless LAN network 2003, the terminal 2001 acquires an access IP address in the wireless LAN network 2003 and performs Mobile IP registration processing on the LMA 2005. The LMA 2005 registers with the mobile network packet relay apparatus 2004 using GPRS. As a result, the connection information of the terminal 2001 is associated with the LMA 2005 of the wireless LAN network 2003, and the packet of the terminal 2001 passes through the LMA 2005.

  In the system shown in FIG. 20, both the mobile network 2002 and the wireless LAN 2003 are routed simultaneously. As a result, when traffic is concentrated on either network, the load between the networks can be distributed.

  As described above, in the specification of the interwork system as shown in FIG. 19, six scenarios from scenario 1 to 6 are defined depending on the form of the interwork. These scenarios stipulate a service that allows a terminal in a wireless LAN area to access a mobile network and a service in which a terminal service continues even when the area of the wireless LAN and the mobile network changes during communication.

  However, in these services, since a terminal and a communication path have a one-to-one correspondence, a network suitable for service data transmission cannot be selected for each service used by the terminal. When the load is concentrated on one of the mobile network 1902 and the wireless LAN network 1903, the user connected to the network on which the load is concentrated is moved to the other network to distribute the load. There is a problem that it cannot be planned.

  On the other hand, in the interwork system shown in FIG. 20, the relationship between the mobile network and the wireless LAN network must be fixed. Specifically, the LMA 2005 needs to hold the address of the mobile network packet relay device 2004 in advance in order to transfer the registration request from the terminal 2001 to the mobile network packet relay device 2004. Also, since the mobile network packet relay device 2004 manages the wireless LAN network 2003 using GPRS connection information, the LMA 2005 is not an IETF standard Mobile IP (IETF RFC3344, “IP Mobility Support for IPv4”). It is necessary to implement GPRS, which is a limited 3GPP standard protocol. Due to such restrictions, when the system shown in FIG. 20 is used, the number of interconnection destinations is limited.

  The present invention has been made in view of such problems, and an object of the present invention is to execute packet distribution processing in both the mobile network and the wireless LAN network, and to switch the connection due to factors on the network side. By using IMS when setting the packet distribution, it is possible to appropriately set the packet distribution processing method even when an unknown network becomes an interconnection target.

  The wireless communication system of the present invention includes a public packet network, a plurality of wireless communication networks each provided with a relay device, a terminal capable of packet connection with the plurality of wireless communication networks, and the public packet network via the public packet network. A counter node that performs packet communication with the terminal, and a router that manages a destination of the terminal that changes according to movement of the terminal, the terminal including a relay device that relays a packet transmitted from the counter node to the terminal The information specifying the relay device is set in the main relay device selected from the plurality of relay devices, and the router sends the packet addressed to the terminal input from the opposite node to the main relay device. The main relay device outputs the packet addressed to the terminal to the IP address of the forwarding device specified for each port number of the terminal, and the relay device is input from the main relay device. Outputting a packet addressed to the terminal to the terminal, the terminal is configured to output a packet addressed to the remote node to the IP address of the transfer destination relay apparatus, which is designated for each port number.

  By adopting such a configuration, it is possible to perform appropriate packet distribution processing even when the destination network of packet data is designated for each port and an unknown network becomes an interconnection target.

  In the above wireless communication system, the main network IMS server that performs call control of packet calls belonging to the wireless communication network of the main network provided with the main relay device, and a packet for each wireless communication network in the area other than the main network A visited network IMS server that performs call control of the call, and the visited network IMS server sets a transfer setting for relaying a packet of a designated port number to a relay device provided in the visited network The processing is executed, and a route change request storing a set of the terminal identifier, the port number, and the IP address of the forwarding destination relay device is output to the main network IMS server, and the main network IMS server responds to the route change request, A transfer setting process for changing the transfer destination of the packet of the designated port number to the transfer destination relay device is executed on the main relay device.

  With this configuration, it is possible to flexibly change the packet data transmission path by specifying the terminal settings and operations by the user, and information about each other's address is stored between the source and destination relay devices. Even if it is not done, the effect is obtained that the transmission path can be switched for each port.

  In the above wireless communication system, the terminal is configured to be able to output a route change request to the main network IMS server or the visited network IMS server, and the visited network IMS server responds to the route change request from the terminal. The transfer setting process is executed.

  With such a configuration, it is possible to perform packet transfer processing in response to a route change request input from the terminal side.

  In the above wireless communication system, the relay device setting unit that outputs the operation information of one relay device selected from the plurality of relay devices, and the operation information output from another relay device other than the one relay device. A relay device that compares the operation information of the one relay device with the operation information of another relay device, and based on the result, the main relay device for switching the main relay device. The relay device change process is executed for another relay device, and the other relay device executes the change process in which the main relay device corresponding to the terminal designated based on the main relay device change process is set as one relay device. Then, the one relay device is configured to output a MIP route change request for registering the address of the one relay device as a care-of address with the change of the main relay device to the router.

  With such a configuration, it is possible to perform packet transfer processing in response to a request from the wireless communication network side, and it is possible to avoid an increase in load and congestion on the wireless communication network side.

  The wireless communication method of the present invention includes steps necessary for wireless communication in the system.

  With this configuration, packet distribution processing is executed in both the mobile network and the wireless LAN network, and even when an unknown network becomes an interconnection target, the packet distribution processing method is set appropriately. Can be made possible.

  The wireless communication system of the present invention performs packet distribution processing in both the mobile network and the wireless LAN network, and even when an unknown network becomes an interconnection target, the packet distribution processing method is appropriately performed. Setting is possible.

  The wireless communication system of the present invention has a function of allowing a user to select a communication network to be used according to the type and characteristics of transmission data, and is useful as a cooperative system using a plurality of communication networks. Further, the present invention can also be applied to uses such as failure avoidance for avoiding a situation where a communication carrier concentrates loads on some networks and nodes or congestion occurs.

  As described below, there are other aspects of the present invention. Accordingly, this disclosure is intended to provide some aspects of the invention and is not intended to limit the scope of the claimed invention.

FIG. 1 is a block diagram showing a system configuration of an interworking system according to the first embodiment of the present invention. FIG. 2 is a block diagram showing an internal configuration of the mobile network packet relay device according to the first embodiment of the present invention. FIG. 3 is a block diagram showing an internal configuration of the packet data relay device according to the first embodiment of the present invention. FIG. 4 is a block diagram showing an internal configuration of the IMS server according to the first embodiment of this invention. FIG. 5 is a block diagram showing the internal configuration of the terminal according to the first embodiment of the present invention. FIG. 6 is a field diagram showing data of the terminal state management unit of the terminal according to the first embodiment of the present invention. FIG. 7 is a field diagram showing data of the terminal state management unit of the mobile network packet relay device according to the first embodiment of the present invention. FIG. 8 is a field diagram showing data of the terminal state management unit of the packet data relay device according to the first embodiment of the present invention. FIG. 9 is a field diagram showing data of the terminal state management unit of the first IMS server in the first embodiment of the invention. FIG. 10 is a field diagram showing data of the terminal state management unit of the second IMS server according to the first embodiment of this invention. FIG. 11 is a field diagram showing data of the terminal state management unit of the home agent according to the first embodiment of the present invention. FIG. 12 is a sequence diagram when the terminal is located in the cell M1 in the first embodiment of the present invention. FIG. 13 is a sequence diagram when the terminal moves to the cell L1 in the first embodiment of the present invention. FIG. 14 is a terminal state transition diagram according to the first embodiment of the present invention. FIG. 15 is a flowchart for explaining the operation of the terminal at the time of location registration according to the first embodiment of the present invention. FIG. 16 is a flowchart for explaining the operation of the terminal during communication according to the first embodiment of the present invention. FIG. 17 is a flowchart for explaining the packet transfer operation of the mobile network packet relay device or the packet data relay device according to the first embodiment of the present invention. FIG. 18 is a sequence diagram showing the operation of the system according to the second embodiment of the present invention. FIG. 19 is a diagram for explaining an outline of a system configuration in which Mobile IPv6 and 3GPP interworking systems are combined. FIG. 20 is a conceptual diagram for explaining the method disclosed in Japanese Patent Application Laid-Open No. 2004-180311.

  The wireless communication system of the present invention will be described below with reference to the drawings. However, the following detailed description and the accompanying drawings do not limit the invention. The scope of the invention is defined by the appended claims.

(First embodiment)
FIG. 1 is a block diagram showing a system configuration of an interworking system according to the first embodiment of the present invention. In FIG. 1, the terminal 101a in the area M1 and the terminal 101b in the area L1 are terminals having the same configuration, and both may be collectively referred to as the terminal 101. Terminal 101 in the present embodiment includes an interface for communicating with mobile network 102 and wireless LAN network 103. The terminal 101 corresponds to a UE (User Equipment) in 3GPP when communicating with the mobile network 102.

  In the example shown in FIG. 1, the terminal 101a is located in the area (M1) of the mobile network 102, and the terminal 101b is located in the area (L1) where both the mobile network 102 and the wireless LAN network 103 can be accessed. is doing. In the following description of the present embodiment, processing when the terminal 101 initially registers its position in the terminal 101a and then starts communication and moves to the position of the terminal 101b will be described.

  The mobile network 102 is a (communication) network that complies with mobile communication standards such as GSM, GPRS, and W-CDMA. In the present embodiment, it is assumed that mobile network 102 is the home network of terminal 101. Here, the home network means a network with which the user of the terminal 101 is contracted, and the visited network means a network to which a cell at a location where the terminal 101 exists belongs.

  The mobile network 102 includes a mobile access network 104, a packet control device 105, and a mobile network packet relay device 106. The mobile access network 104 has a radio interface of the mobile network 102 and transmits data of the mobile network 102 and corresponds to 3GPP UTRAN. The packet control device 105 performs GPRS connection setting of the terminal 101, and corresponds to 3GPP SGSN. The mobile network packet relay device 106 corresponds to a 3GPP GGSN and relays packets between the mobile network 102 and the public packet network 112.

  The wireless LAN network 103 has a wireless LAN interface such as IEEE802.11 / 11a / 11b / 11g / 11n and HIPERLAN and transmits packets. The wireless LAN network 103 includes a WLAN access network 108, a WLAN relay device 109, and a packet data relay device 110.

  The WLAN access network 108 provides a terminal with a wireless LAN connection, and corresponds to a 3GPP WLAN AN (Access Network). The WLAN relay device 109 is connected to the WLAN access network 108 and relays a packet accessible to the mobile network 102. The packet data relay device 110 relays the wireless LAN packet to the public packet network 112.

  The first IMS server 107 performs IMS call control processing related to terminals existing in the mobile network 102. The first IMS server 107 corresponds to an S-CSCF (Serving-CSCF) of 3GPP. The second IMS server 111 connected to the first IMS server 107 relays a signal related to IMS call control processing related to a terminal existing in the wireless LAN network 103, and corresponds to a 3GPP P-CSCF. The first IMS server 107 and the second IMS server 111 may be collectively referred to simply as “IMS server”.

  The user information storage device 113 manages the connection state of the terminal 101 and corresponds to a 3GPP HLR (Home Location Register) or HSS (Home Subscriber Server). The authentication system 114 connected to the user information storage device 113 relays an authentication signal with the user information storage device 113 when performing authentication from the wireless LAN. The authentication system 114 corresponds to one or both of 3GPP AAA Proxy / AAA Server.

  The public packet network 112 is connected to the mobile network 102 and the wireless LAN network 103. The public packet network 112 is a network for exchanging packets in the public, and corresponds to a 3GPP PDN (Packet Data Network). The public packet network 112 is connected to a home agent 115 that is a router that supports movement of the mobile node and an opposite node 116. The home agent 115 is a Mobile IP home agent, and the opposite node 116 communicates with the terminal 101.

  FIG. 2 is a block diagram showing an internal configuration of the mobile network packet relay device 106. In this figure, a GGSN connection setting unit 201 performs connection setting for the terminal 101 that uses the mobile network packet relay apparatus 106. The terminal status management unit 202 manages the connection status related to the terminal 101 using the mobile network packet relay device 106. The PDG state management unit 203 acquires and manages an operation state such as a load of the packet data relay apparatus 110. The packet relay unit 204 inputs and outputs packet data between the packet control device 105, the packet data relay device 110, and the public packet network 112 and the mobile network packet relay device 106.

  The SGSN communication unit 205 performs protocol processing with the packet control device 105 and inputs / outputs communication data. The PDG / PDN communication unit 206 inputs and outputs packets between the packet data relay device 110 and the public packet network 112. In the present embodiment, it is assumed that these and mobile network packet relay apparatus 106 are both connected via IP. Further, the IMS communication unit 207 performs communication of call control data between the mobile network packet relay device 106 and the “IMS server”.

  FIG. 3 is a block diagram showing an internal configuration of the packet data relay apparatus 110. In FIG. 3, the PDG connection setting unit 301 performs connection settings regarding the terminal 101 that uses the packet data relay apparatus 110. The terminal state management unit 302 manages the connection state regarding the terminal 101 that uses the packet data relay device 110. The GGSN state management unit 303 performs protocol processing with the mobile network packet relay device 106 and input / output of communication data. The packet relay unit 304 inputs and outputs packet data between the WLAN relay device 109, the mobile network packet relay device 106, and the public packet network 112 and the packet data relay device 110.

  The WAG communication unit 305 performs protocol processing with the WLAN relay device 109 and input / output of communication data. The GGSN / PDN communication unit 306 inputs and outputs packets between the mobile network packet relay device 106 and the public packet network 112. It is assumed that the mobile network packet relay device 106, the public packet network 112, and the packet data relay device 110 are all connected via IP. Then, the IMS communication unit 307 performs call control data communication between the mobile network packet relay device 106 and the IMS server.

  FIG. 4 is a block diagram showing an internal configuration of the IMS server. In this figure, the terminal control unit 401 performs connection settings relating to the terminal 101 using the “IMS server”. The terminal state management unit 402 manages the state of call control related to the terminal 101 using the IMS server. The transfer setting unit 403 performs setting for transferring the call control message according to the terminal 101. The IP communication unit 404 performs IP transmission and Mobile IP processing.

  The packet network communication unit 405 communicates with the public packet network 112. The IMS communication unit 406 communicates with another “IMS server”. The GGSN / PDG communication unit 407 inputs / outputs packets between the mobile network packet relay device 106 and the packet data relay device 110. It is assumed that the mobile network packet relay device 106, the packet data relay device 110, and the IMS server are all connected via IP.

  FIG. 5 is a block diagram showing an internal configuration of the terminal 101. In FIG. 5, a terminal call control unit 501 performs call control related to the terminal 101, generates a message to the IMS server, and has a function of IMS and SIP protocol processing. The terminal state management unit 502 manages various states related to the terminal 101. The path control unit 503 determines an appropriate transmission path according to the application or connection. The IP communication unit 504 performs IP communication for the terminal 101. The IP distribution communication unit 505 refers to the terminal state management unit 502, distributes packets according to the type of network, and determines a packet communication destination.

  The GPRS communication unit 506 performs a protocol process related to GPRS. The mobile access network communication unit 507 communicates with the mobile access network 104 and performs radio control. The WLAN access IP communication unit 508 communicates with the packet data relay device 110 using the access IP address of the wireless LAN network. The WLAN communication unit 509 communicates with the WLAN access network 108.

  6 is a field diagram showing data of the terminal status management unit of the terminal 101, FIG. 7 is a field diagram showing data of the terminal status management unit of the mobile network packet relay device 106, and FIG. 8 is a terminal status management of the packet data relay device 110. FIG. 9 is a field diagram showing data of the terminal status management unit of the first IMS server 107, FIG. 10 is a field diagram showing data of the terminal status management unit of the second IMS server 111, and FIG. It is a field diagram which shows the data of the terminal state management part of the agent 115. FIG.

Hereinafter, the meanings of addresses and the like shown in the field diagrams of FIGS. 6 to 11 will be described.
“Terminal ID” (601, 701, 801, 901, 1001, 1101) is an identifier for uniquely identifying a terminal. As this terminal ID, for example, IMSI, NAI (Network Access Identifier), SIP URI, SIP URL, or the like can be used.

  “Access IP address” (605, 606, 702, 802) is an IP address used when the terminal 101 accesses the mobile network 102 or the wireless LAN network 103. In the present embodiment, the home agent 115 exists outside the mobile network 102 and the wireless LAN network 103. Therefore, it is not guaranteed that the home IP address (described later) handled by the home agent 115 can be routed in both networks. When the terminal 101 performs access, it is necessary to obtain an access IP address that can be routed within the access network from the network that performs access.

  “Home IP address” (607, 703, 803, 1103) is an IP address used when the terminal 101 accesses the mobile network 102 and the outside of the wireless LAN network 103. In the present embodiment, in order to provide mobility of the terminal 101 for both the mobile network 102 and the wireless LAN network 103, a home IP address is used when accessing the outside. In this embodiment, it is assumed that terminal 101 has a home IP address in advance, but the same effect can be obtained even when the home IP address is acquired at the start of access.

  “Used port number” (609, 704, 804) is a port number such as TCP, UDP, SCTP, etc., used by the terminal 101 for transmission of the communication service, and is a transmission path for transmission to or from the same address. It is a number for distinguishing. In the field diagram, only the examples of the port numbers “Pa” and “Pv” are shown, but the value of “default” can also be specified to indicate the specification for other port numbers. For example, if “default” is specified in addition to “Pa” and “Pv”, it indicates all port numbers other than “Pa” and “Pv”.

  In FIG. 6, “terminal state” 602 indicates the communication state of the terminal, and has three types of states: “stop”, “standby”, and “in communication”. “GPRS connection information” 603 is connection information related to GPRS and corresponds to the PDP context of 3GPP TS 23.060. “WLAN connection information” 604 is information stored for connection to the wireless LAN network 103. Examples of the “WLAN connection information” include a WEP key for connecting to the WLAN access network 108, an ESS-ID, an authentication method, an authentication ID, a password, and the like, and an access IP address assigned to the terminal after connection. “IMS server address” 608 is the address of the IMS server used by the terminal. “Used network relay device IP address” 610 is an IP address of a relay device of either the mobile network 102 or the wireless LAN network 103 used for packet communication from the terminal 101 to the home agent 115. The “used network relay device IP address” 610 is assigned to each “used port number” 609.

  7 and 8, the forwarding destination relay device IP address (705, 805) indicates an address that is a transmission destination of a downlink packet (addressed to the terminal 101) of the corresponding use port. The transfer destination relay device IP address (705, 805) is assigned to each used port number (704, 804). The main relay device IP address (706, 806) indicates the IP address of the main relay device. Note that the main relay device is a relay device to which a care-of address registered in the home agent is assigned for each terminal, and specifically, a mobile network packet relay device or a packet data relay device. GPRS connection information (707, 807) is connection information related to GPRS and corresponds to a PDP context in 3GPP.

  9 and 10, the terminal IP address (902, 1002) is the IP address of the terminal 101. The home server IP address (903, 1003) is the IP address of the IMS server of the home network of the terminal 101. In the present embodiment, the home network of terminal 101 is assumed to be mobile network 102, and wireless LAN network 103 is the visited network of terminal 101.

  In FIG. 11, a care-of address 1102 is a care-of address used in Mobile IP. In the case of Mobile IPv4 assumed in the present embodiment, the address of a relay device that is a Foreign Agent (FA) is used.

  Below, with reference to FIGS. 12-17, the operation | movement of the system in this Embodiment is demonstrated.

  FIG. 12 is a sequence diagram when the terminal 101 is located in the cell M1 and becomes the terminal 101a, and FIG. 13 is a sequence diagram when the terminal 101a moves to the cell L1 and becomes the terminal 101b.

  FIG. 14 is a state transition diagram of terminal 101 in the present embodiment. As shown in FIG. 14, the terminal 101 has three states of “stop” 1401, “waiting” 1402, and “communication” 1403 depending on power on / off, stay area, and communication start / completion. Take. The state of the terminal 101 is stored in the terminal state 602 field of the terminal state management unit 502.

  FIG. 15 is a flowchart for explaining the operation of terminal 101 at the time of location registration in this embodiment, FIG. 16 is a flowchart for explaining the operation of terminal 101 during communication, and FIG. 17 is a mobile network packet. It is a flowchart for demonstrating the operation | movement of the packet transfer of a relay apparatus or a packet data relay apparatus.

  A sequence when the terminal 101 is located in the cell M1 and becomes the terminal 101a will be described with reference to FIG. A state 1201 indicates that the terminal 101a is “stopped” 1401 (FIG. 14). When the terminal 101a is powered on by the user, the powered terminal 101a outputs GPRS location registration / user information registration 1202. In the process of outputting the GPRS location registration / user information registration 1202, the terminal 101a performs the processes from step S1501 to step S1503 in FIG. That is, first, a connectable network is detected (step S1501). Here, it is assumed that the terminal 101a can communicate only with the mobile network 102. Next, the type of the detected network is determined (step S1502). If it is determined that the detected network is a mobile network, the process proceeds to the GPRS connection process (step S1503), and the position M1 of the terminal ID1 is registered in the mobile packet relay apparatus 106 by this process.

  In this GPRS connection process (step S1503), the terminal 101a notifies the mobile network packet relay device 106 that the registration is registration of the first network after power-on. The mobile network packet relay device 106 registers its own address IPg as the main relay device IP address of the terminal 101a. The terminal 101a acquires the access IP address IPa on the mobile network 102 side from the mobile packet relay apparatus 106. At this time, the following processing is performed inside the terminal 101a.

  When the power of the terminal 101a is turned on, the GPRS communication unit 506 of the terminal 101a starts a GPRS location registration process, outputs a request to the packet control device 105, and inputs a response. The mobile access network communication unit 507 Do through. In the terminal 101a, the GPRS communication unit 506 performs packet communication with the mobile network packet relay apparatus 106 of the mobile network 102. In the GPRS location registration / user information registration 1202 process, the GPRS communication unit 506 is basically used to perform the same process as the GPRS protocol. Location registration processing performed between the terminal 101a and the packet control device 105 includes ATTACH processing and authentication processing for performing location registration. In 3GPP TS 23.060, ATTACH Request / Response / Accept / Complete, Identity Request / Response. The process is executed according to the IMEI Check procedure.

  When the GPRS location registration / user information registration 1202 is input, the packet control device 105 performs GPRS connection setting. In this GPRS connection setting, the packet control device 105 creates (primary) GPRS connection information (PDP context in 3GPP) for the packet control device 105 corresponding to the terminal 101, and starts managing the position of the terminal 101 in the mobile network 103 To do. Further, in GPRS connection setup, the packet controller 105 performs location update processing (Location Update Request / Response in 3GPP), creation processing of (primary) GPRS connection information to the mobile network packet relay device 106 (Create PDP Context in 3GPP). Request / Response) and location update processing (routing area update in 3GPP) to the user information storage device 113 is performed.

  When the GPRS location registration / user information registration 1202 is input, the mobile network packet relay device 106 creates (secondary) GPRS connection information (Secondary PDP context in 3GPP) and passes the access IP address IPa to the terminal 101a. . Then, the terminal 101 a stores the access IP address IPa for the mobile network 102 in the terminal state management unit 502. In the following, when simply describing GPRS connection information, it means GPRS connection information for mobile network packet relay devices.

  The access IP address IPa is assigned by a node outside the mobile network packet relay device 106 such as the public packet network 112 and transmitted to the terminal 101a via the mobile network packet relay device 106.

  At this time, in the mobile network packet relay device 106, first, a request from the terminal 101 a is input to the SGSN communication unit 205 via the packet control device 105. Since the request from the terminal 101a is related to GPRS location registration, the GGSN connection setting unit 201 creates GPRS connection information for the mobile network packet relay device corresponding to the terminal 101, and the terminal state management unit 202 Is stored as GPRS connection information 707.

  Further, since the mobile network packet relay device 106 is the first relay device to which the terminal 101 a is connected, the mobile network packet relay device 106 stores the IP address IPg of the mobile network packet relay device 106 as the main relay device IP address 707. The mobile network packet relay apparatus 106 stores the access IP address IPa in 702 as the access IP address. After creating the GPRS connection information, the GGSN connection setting unit 201 generates a response and outputs the response to the packet control apparatus 105 via the SGSN communication unit 205.

  Further, the packet control device 105 receives the GPRS location registration / user information registration 1202 and registers the terminal ID and the connected location (cell M1) in the user information storage device 113. Here, Update Location / Ack and Insert Subscriber Data message in 3GPP are used. As a result of the above processing, communication by GPRS of the terminal 101a becomes possible.

  The terminal 101a outputs the MIP registration 1203. Before outputting the MIP registration 1203, the terminal 101a registers the access IP address IPa of the mobile network 102 together with the home IP address as a care-of address in the home agent 115 in the Mobile IP setting process (step S1506). Before executing Step S1506, the terminal 101a separately acquires the IP address of the home agent 115 and the home IP address of the terminal 101a and stores them in the terminal state management unit 502. For example, the terminal 101a may always hold the home IP address in the terminal state management unit 502, or a method of separately authenticating with the service provider of the home agent and distributing it when the authentication is completed is possible.

  In the terminal 101a, when GPRS communication setting by the GPRS communication unit 506 is completed, the access IP address is notified to the terminal call control unit 501 via the IP distribution communication unit 505 and the IP communication unit 504. The terminal call control unit 501 registers the access IP address IPa in the terminal state management unit 502 together with the terminal 101a (terminal ID is ID1). When this registration is completed, the terminal call control unit 501 creates a MIP registration 1203 that is a request for registering the terminal 101a in the home agent 115, and the IP communication unit 504 and the IP distribution communication unit 505 send an IP packet for an external network. The MIP registration 1203 is output to the mobile access network 104 via the GPRS communication unit 506 and the mobile access network communication unit 507. In the subsequent processing, all IP packets passing through the mobile network 102 are input / output using this route.

  As shown in FIG. 12, the MIP registration 1203 is input to the home agent 115 via the mobile access network 104, the packet control device 105, the mobile network packet relay device 106, and the public packet network 112. This MIP registration 1203 is a signal including Mobile IP Registration Request / Reply.

  The home agent 115 registers the access IP address IPa as the terminal ID 1101 ID1 and the access IP address 1102, and registers the home IP address IPc as the home IP address 1103 in association with the access address IPa. After this registration is completed, the home agent 115 outputs a response indicating registration success to the terminal 101a. When this response is input, in the terminal 101a, the terminal call control unit 501 registers a set of ID1 that is the terminal ID of the terminal 101a and the home IP address IPc in the terminal state management unit 502.

  IMS server search / SIP registration 1204 is a signal that the terminal 101a outputs to the first IMS server. Before the IMS server search / SIP registration 1204 is output, the terminal 101a performs the SIP setting process S1507 when the Mobile IP process is completed. In IMS server search / SIP registration 1204, the terminal 101 a searches for an IMS server related to the mobile network 102, and stores the IP address in the terminal state management unit 502 when the IMS server is detected. At this time, the address IPs of the first IMS server 107 that is an IMS server that controls the terminals under the mobile network 102 is acquired from the mobile network 102.

  Note that 3GPP TS23.228 (3GPP TS23.228, “IP Multimedia Subsystem (IMS); Stage 2”) describing the IMS specification is linked with the DHCP server of the mobile network 102 and the DNS server in cooperation with the IP of the IMS server. A mechanism for notifying the address to the terminal 101a is shown. There is also a method for obtaining the IP address of the IMS server from the mobile packet relay device 106 or the packet control device 105.

  The terminal 101 a outputs an IMS server search / SIP registration 1204 to the first IMS server 107. This signal corresponds to IETF SIP Registration. When the IMS server search / SIP registration 1204 is output, the following processing is performed inside the terminal 101a.

  When the terminal call control unit 501 acquires the IP address IPs of the first IMS server 107, the terminal call control unit 501 creates a SIP registration request and outputs it to the mobile network 102 in order to perform registration processing with the first IMS server 107. When the IMS server search / SIP registration 1204 is input by the terminal 101a, the terminal 101a executes the SIP registration processing to the first IMS server 107, and the user ID and the home IP address IPc of the terminal 101a are stored in the user information storage device 113. be registered. In TS23.228, “public user identity” (telephone number, RFC URI 3261 SIP URI or RFC2806 tel URL) or “private user identity” (NAI form is used by Cx-Put / Cx-Pull. "S-CSCF name" is output.

  In the first IMS server 107, first, the GGSN / PDG communication unit 407 performs IP protocol processing in the IP communication unit 404 up to the MAC layer (Media Access Control layer) which is a part of the data link layer, and the IMS server. When the search / SIP registration 1204 is input, the terminal control unit 401 analyzes the message. In this case, since it is SIP registration for the home network, the terminal control unit 401 sets ID1 and home IP address IPc as a set of the terminal ID 901, home IP address 902, and home server IP address 903 input to the terminal state management unit 402, respectively. The IP address IPs of the first IMS server 107 is registered. Thereafter, a response indicating the completion of registration is output to the terminal 101b via the IP communication unit 404 and the GGSN / PDG communication unit 407. In the terminal 101a, the IP address IPs of the first IMS server 107 is registered in the IMS server IP address 608 of the terminal state management unit 502.

  When the SIP registration processing of IMS server search / SIP registration 1204 is completed in the terminal 101a, the series of processing illustrated in FIG. 15 is completed, and the terminal 101a is in the “waiting” state 1402 (state 1205) (FIG. 14). It becomes. Here, the terminal call control unit 501 in the terminal 101a changes the state in the terminal state management unit 502 to “standby”.

  When the SIP registration is completed, in the SIP call processing 1206, the terminal 101a uses the first IMS server 107 to make a SIP call to the opposite node (ID2). The transmission starts with a SIP INVITE message, and “Offer”, “Reservation”, “Ringing”, “OK”, and “ACK” messages are transmitted and received. These signals are relayed by the mobile network 102 and the first IMS server 107 and output to the opposite node.

  When the series of processing is completed, the terminal 101a starts outputting the terminal data stream (signal 1207) to the acquired IP address of the opposite node as shown in FIG. Further, the terminal 101b stores in the terminal state management unit 502 that both the voice use port Pa and the video use port Pv are via the mobile network packet relay device 106.

  When the terminal 101a completes the output of the SIP call processing 1206, the terminal 101a enters a “communication” state 1403 (FIG. 14) in a state 1208. Here, the terminal call control unit 501 in the terminal 101 a changes the state in the terminal state management unit 502 to “in communication” 1403. This time is “time (a)”, and data stored in the node at this time is shown in “(a)” in FIGS.

  Next, the operation of the system of this embodiment when the terminal 101a moves to the cell L1 and becomes the terminal 101b will be described using the sequence diagram of FIG. 13 and the flowchart of FIG. FIG. 13 shows a sequence continued from FIG.

  FIG. 16 is a flowchart for explaining processing from network detection to network selection in the “in communication” state 1403. At the first time point in FIG. 13, the terminal 101a moves to the cell L1 and becomes the terminal 101b in the last cell L1 entry 1209 in FIG. The terminal 101b detects the wireless LAN network 103 as a connectable network through “connectable network detection / connection process” (step S1601) in FIG. 16, and this is referred to as “network A” in process S1601. Execute the connection process.

  In the WLAN connection setting 1301 illustrated in FIG. 13, the terminal 101 b performs the WLAN connection setting for the entered wireless LAN network 103. First, the WLAN access network 108 that has detected the terminal 101 b performs WLAN connection setting, and issues a local IP address IPb that the terminal 101 b uses when connecting to the wireless LAN access network 108. In the terminal 101b, the WLAN communication unit 509 performs physical layer and MAC layer communication processing with the WLAN access network. The WLAN communication unit 509 receives a beacon output from the WLAN access network 108 or detects an access point of the WLAN access network 108 and performs connection processing of the wireless LAN network 103 and authentication processing as necessary.

  Here, if the standard of the wireless interface used by the wireless LAN network 103 is IEEE802.11, Beacon and Probe Request / Response are used for the connection processing, and an Authentication Request / Response message is used for the authentication processing. In the authentication process, the NAI of the terminal can be used in addition to the terminal ID.

  After the connection process to the MAC layer, the WLAN communication unit 509 acquires the local IP address IPl in the wireless LAN network 103. The local IP address may be acquired simultaneously with the authentication process.

  Inside the terminal 101b, the WLAN communication unit 509 outputs the terminal ID by an authentication procedure determined by the wireless LAN network 103, and the WLAN access network 108 performs authentication. As a result of authentication, if it is determined that the WLAN access network 108 can be accessed with the terminal ID of the terminal 101b, the WLAN access network 108 responds and inputs the local IP address IPl to the WLAN communication unit 509. Further, the local IP address IPl is stored as the WLAN connection information 604 in the terminal state management unit 502.

  When connection to the wireless LAN network 103 becomes possible, the terminal 103b performs a series of processes shown in FIG. 16, that is, a process for selecting a network to be connected during communication. In this case, a determination is made to change the moving image use port Pv from the mobile network 102 to the wireless LAN network 103.

  The terminal 101 b obtains the access IP address IPb of the wireless LAN network 103 via the packet data relay device 110 and stores it as the access IP address 606 for the wireless LAN network 103 in the terminal state management unit 502. The access IP address IPb is a remote IP address in the interworking use specified by 3GPP TS23.234. Thereafter, the terminal 101b can communicate via the packet data relay device 110 and the WLAN relay device 109.

  Inside the terminal 101b, the WLAN access IP communication unit 508 selects the wireless LAN network 103 accessible from the WLAN access network, and outputs an authentication request including the terminal ID ID1 to the authentication system 114. If the terminal 101b can communicate with the wireless LAN network 103, an authentication response indicating permission is input to the terminal 101b. Thereafter, a setting process for establishing a tunnel between the terminal 101b and the packet data relay apparatus 110 is performed, and communication is started. During this process, the WLAN connection information 604 is stored in the terminal state management unit 502.

  After the above process, when the terminal 101b communicates with the wireless LAN network 103, the WLAN access IP communication unit 508 performs an encapsulation process for communicating with the packet data relay apparatus 110 inside the terminal 101b. The WLAN communication unit 509 performs processing of the physical layer and the MAC layer of the wireless LAN and encapsulation processing using a local IP address in the wireless LAN network 103. In the following, when it is described that “the terminal 101b communicates with the wireless LAN network 103”, it is assumed that these processes are performed in the terminal 101b.

  The terminal 101b searches for the IP address IPp of the packet data relay apparatus using a DNS server (not shown). Inside the terminal 101b, the WLAN access IP communication unit 508 acquires the IP address IPp of the packet data relay apparatus 110. As a result, the terminal 101b and the wireless LAN network 103 can be connected, and step S1601 is completed.

  In “acquiring a network during communication” (step S1602), the terminal 101b acquires the mobile network 102, which is a network during communication, and sets this as “network B”. Then, in “network A ≠ network B” (step S1603), which is a process for determining whether or not the networks match, network A that can be connected is compared with network A that is in communication. Here, since the network B that is in communication is different from the network A that can be connected, the process proceeds to “Extraction of uncommunication & connectable network” (step S1604). In the network comparison process in step S1603, the IP address IPg of the mobile network packet relay device 106 of the mobile network 102 is acquired as the address of the relay device being used, and the packet data relay that is the relay device of the wireless LAN network 103 is acquired. The IP address corresponding to the mobile network 102 and the IPb corresponding to the wireless LAN network 103 are determined to be different from the IP address IPp of the device 110 or assigned to each network connected to the terminal 101. May be determined to be different.

  In step S1604, a network that is not communicating and can be connected is extracted, and is set as “network C”. At this time, in the terminal 101b, the wireless LAN network 103 matches the condition and is extracted.

  Thereafter, the port and service used by the terminal 101b for communication are extracted by “extract used port and service” (step S1605). The terminal 101b uses the port Pv for moving picture transmission and the port Pa for voice transmission.

  Step S1606 is a process of “outputting a request for switching from the network B to the network C with respect to a port used by the network C better than the network B”. In this process, the network switching process is performed for the port number of the service determined to have a higher priority than the network (network B) that is newly connectable in step S1604 above the network (network B) in communication. . In this embodiment, it is assumed that the mobile network 102 with a wide area is used for voice transmission at the port Pa, and the wireless LAN network 103 with a wide band is used for video transmission. Therefore, the port to be switched is only the port Pv and the switching destination is the wireless LAN network 103.

  In the following, the transmission path switching process of the port Pv will be described in the order of the IMS server search and the switching request process.

  In the IMS server search 1302, the terminal 101b searches for the IMS server and acquires the address IPt of the second IMS server 111. Further, the terminal 101b outputs the SIP registration 1303 of the terminal ID1 to the second IMS server 111. In that case, a SIP Registration message is used.

  The communication process between the second IMS server 111 and the terminal 101b is the same as the IP address acquisition process of the first server in the first IMS server 107. However, in this case, since the mobile network 102 is the home network of the terminal 101, the wireless LAN 103 is a visited network. Therefore, since the S-CSCF in the IMS specification of TS 23.228 is the first IMS server 107, the second IMS server 111 performs the operation of the P-CSCF. First, the IMS server of the second IMS home network is searched using the user ID of the terminal 101b. As a result, the first IMS server 107 and its IP address IPs are searched, and a connection between the second IMS server 111 and the first IMS server 107 is formed.

  At this time, the second IMS server 111 performs processing as follows. When the SIP registration 1303 by the terminal 101a is input, the second IMS server 111 performs SIP registration processing on the second IMS server 111. At this time, in the second IMS server 111, when the GGSN / PDG communication unit 407 first performs IP protocol processing in the IP communication unit 404 up to the MAC layer and the SIP registration 1303 is input, the terminal control unit 401 Parses the message. In this case, since it is SIP registration for the visited network, the terminal control unit 401 passes a request to the transfer control unit 403.

  The transfer control unit 403 performs processing for searching for an IMS server in the home network using the user ID as a key in cooperation with the user information storage device 113 via the IP communication unit 404 and the GGSN / PDG communication unit 407. As a key at this time, IMSI, a domain name extracted from the user ID, a GGSN address, or a GGSN number may be used in addition to the user ID.

  When the search is completed, the IP address IPs of the first IMS server 107 is registered in the terminal state management unit 402 together with the user ID of the terminal 101b. Thereafter, a signal from the terminal 101 b is output to the first IMS server 107. The first IMS server 107 registers the terminal 101b and outputs a response to the second IMS server 111, as in the home network. Then, the second IMS server 111 outputs the above response as it is to the terminal 101b. In the terminal 101b, the terminal control unit 501 stores the IP address IPt of the second IMS server 111 in the terminal state management unit 502 as the IMS server IP address 608.

  Thereafter, an IMS-related call control signal is transmitted from the terminal 101b via the wireless LAN network 103 and the second IMS server 111 through a path called the first IMS server 107. This time is “time (b)”, and the data stored in the node at this time is shown in “(b)” in FIGS.

  The terminal 101b changes the stream related to the home IP address IPc related to the video port Pv from the IP address IPa via the mobile network 102 to the IP address IPb via the IP address IPp of the packet data relay device 110 of the wireless LAN network 103. The route change request 1304 to be output is output to the second IMS server 111.

  Inside the terminal 101 b, the terminal call control unit 501 generates a route change request 1304 and outputs it to the wireless LAN network 103. The route change request 1304 includes a terminal ID ID1 of the terminal 101b, a home IP address IPc, a terminal (access) IP address IPa before the change, a terminal (access) IP address IPb after the change, and an IP address of the transfer destination relay device IPp, port number Pv, and terminal ID ID1 are acquired from the terminal state management unit 502 and stored.

  When the path change request 1304 is input, the second IMS server 111 outputs a transfer setting request 1305 specifying a transfer target stream and a transfer destination to the packet data relay apparatus 110. Further, the second IMS server 111 transfers the route change request 1306 as it is to the first IMS server 107.

  A route change request 1304 is input by the GGSN / PDG communication unit 407 inside the second IMS server 111. The terminal control unit 401 analyzes the route change request 1304 detected from the IP communication unit 404 and detects that it is a route change request. The terminal control unit 401 uses the IP communication unit 404 and the IMS communication unit 406 to output a route change request 1304 to the first IMS server 107 having the home server IP address IPs.

  When the path change request 1306 is input from the second IMS server 111, the first IMS server 107 searches the mobile network packet relay apparatus 106 from the terminal ID ID1 or the terminal IP address IPa before the change, and outputs a transfer setting request 1307. . Inside the first IMS server 107, a route change request 1306 is input via the IMS communication unit 406 and the IP communication unit 404. The terminal control unit 401 analyzes the route change request 1306, and determines the terminal IP address IPa before the change, the terminal IP address IPb after the change, the IP address IPp of the transfer destination relay device, the port number Pv, and the terminal ID ID1. Extract.

  Here, since the gateway of the terminal 101 to the public packet network is the mobile network packet relay device 106, the terminal control unit 401 uses the terminal ID ID1 included in the route change request 1306, the terminal IP address IPa before the change, and the transfer destination. A transfer setting request 1307 for requesting a transfer change storing the IP address IPp of the relay device and the port number Pv is generated, and is transmitted to the mobile network packet control device 106 via the IP communication unit and the GGSN / PDG communication unit 407. Output.

  When a signal for requesting transfer change is input in the transfer setting request 1307, the mobile network packet relay device 106 compares the IP address of the transfer destination relay device in the signal with its own IP address. In this case, since the IP address IPp of the transfer destination relay device is different from the IP address IPg of the main relay device 707, the setting of the transfer destination relay device IP address 705 is changed to IPp for the port Pv specified by the signal.

  In the mobile network packet relay device 106, when a transfer setting request 1307 is input to the GGSN connection setting unit 201 via the IMS communication unit 207, the GGSN connection setting unit 201 determines that the terminal state management unit 302 is based on the terminal ID ID1. The internal main relay device IP address 706 is searched. The GGSN connection setting unit 201 adds the used port number Pv and the transfer destination IP address IPp to the terminal state management unit 202 because the designated transfer destination relay device IP address IPp is different from the IPg of the main relay device IP address 706. Then, the GGSN connection setting unit 201 outputs a signal for confirming the transfer change to the first IMS server 107 via the IMS communication unit 207. If the specified forwarding destination relay device IP address and the main relay device IP address 706 are the same and there is an entry related to the port specified by the signal, the entry is deleted.

  When the transfer setting process is completed, the first IMS server 107 outputs a path change confirmation 1308 that is a response to the path change request to the second IMS server 111. The terminal control unit 401 of the first IMS server 107 stores information (eg, a terminal ID or an identifier uniquely assigned to a message) for associating with the route change request 1306, generates a route change confirmation 1308, and performs IP communication. The data is output to the terminal 101b via the unit 404 and the GGSN / PDG communication unit 407.

  When the path change confirmation 1308 is input from the first IMS server 107, the second IMS server 111 performs a transfer change process for receiving and changing the transfer setting 1309 of the packet data relay apparatus 110, which is a relay apparatus of its own network. As a result, the setting of the packet data relay device 110 is changed.

  When the packet data relay apparatus 110 receives the transfer setting 1309 and receives a signal for requesting transfer change in the transfer change process, the packet data relay apparatus 110 compares the IP address of the transfer destination relay apparatus in the signal with its own IP address. In this case, since the IP address IPp of the transfer destination relay device is different from the IP address IPg of the main relay device 807, the setting of the transfer destination relay device IP address 805 is changed to IPp for the port Pv specified by the signal.

  In the mobile network packet relay apparatus 106, when a transfer setting request 1307 is input to the GGSN connection setting unit 201 via the IMS communication unit 207, the GGSN connection setting unit 201 starts from the terminal IDID1 to the main state in the terminal state management unit 302. The relay device IP address 806 is searched. Since the designated transfer destination relay device IP address IPp is different from the IPg of the main relay device IP address 806, the GGSN connection setting unit 201 adds the used port number Pv and the transfer destination IP address IPp to the terminal state management unit 202. Then, the GGSN connection setting unit 201 outputs a signal for confirming the transfer change to the first IMS server 107 via the IMS communication unit 207. If the specified forwarding destination relay device IP address and the main relay device IP address 806 are the same and there is an entry related to the port specified by the signal, the entry is deleted.

  When the setting of the packet data relay device 110 is completed, the second IMS server 111 outputs a route change confirmation 1310 to the terminal. The terminal control unit 401 of the second IMS server 111 stores information (for example, an identifier uniquely assigned to a terminal ID or a message) to be associated with the route change request 1304, generates a route change confirmation 1308, and performs IP communication. The data is output to the terminal 101b via the unit 404 and the GGSN / PDG communication unit 407.

  When the processing is completed, the terminal 101b stores a set of the port Pv and the access IP address IPp for the port Pv in the terminal state management unit 502.

  This completes the switching process. Thereafter, in the mobile network packet control device 106 and the packet data relay device 110, the IP packet transfer 1311 related to the voice data and the IP packet transfer 1312 related to the moving image data are performed as follows.

  FIG. 17 is a flowchart for explaining the packet transfer operation of the mobile network packet relay device 106 or the packet data relay device 110 in the present embodiment. Hereinafter, this flow will be described in three cases. .

  The first relates to the packet transfer operation from the terminal 101b to the opposite node 116, and the processing of the mobile network packet relay device 106 corresponds to this. Since the mobile network packet relay device 106 becomes the main relay device of the terminal 101b, it is determined “Yes” in the branch of step S1701 to determine whether it is the home network relay device of the terminal 101b, and the process proceeds to step S1702. In step S1702, it is determined whether or not the transfer source is a home agent. Since the transfer source is the terminal 101b, “Yes” is determined and the process proceeds to step S1703. In step S1703, the transfer destination IP address is set as the IP address of the home agent.

  The second relates to the packet transfer operation from the terminal 101b to the opposite node 116, and the processing of the packet data relay apparatus 110 corresponds to this. The packet data relay device 110 becomes a relay device of the wireless LAN network 103 which is the visited network of the terminal 101b. Therefore, in the branch of step S1701, “No” is determined and the process proceeds to step S1705. In step S1705, it is determined whether or not the transfer source is a home agent. Since the transfer source is the terminal 101b, “Yes” is determined, and the process proceeds to step S1706. In step S1706, the transfer destination IP address is set as the IP address of the main relay device. Note that the transfer destination IP address in this case is IPg which is the IP address of the mobile network packet relay device 106.

  The third is a packet transfer operation from the opposite node 116 to the terminal 101b. In this case, regardless of the position of the terminal, the determination results in steps S1702 and S1705, which are the same / non-identical determinations of the transfer source and the home agent, are both “No”, and the process proceeds to step S1704. In step S1704, the transfer destination IP address is selected from the terminal and the port number. Here, if the port number is Pv, the transfer destination IP address is IPp, and if the port is Pa, the transfer destination IP address is IPg.

  In the terminal 101, either the GPRS communication unit 506 or the WLAN access IP communication unit 508 is used by the IP distribution communication unit 505 to use the used network relay device IP address 610 corresponding to the used port number 09 in the terminal state management unit 502. The communication unit to be used is selected, and the IP packet is transferred to the used network relay device IP address 610.

  After the transfer destination IP address is determined, step S1507 is executed to output the relay target IP packet to the transfer destination IP address. This time is “time (c)”, and the data stored in the node at this time is shown in “(c)” in FIGS.

  The above is the content of the packet transmission branch setting process when a terminal enters the wireless LAN network 103 during communication with the mobile network 102. The embodiment described so far depends on the usage of the system. Needless to say, it can be changed as appropriate.

  For example, when a terminal enters the mobile network 102 during communication with the wireless LAN network 103 as in the case where the terminal enters the wireless LAN network 103 during communication with the mobile network 102, the wireless LAN A mobile network packet relay device in which the IMS server is a control target even when entering another wireless LAN network during communication with the network 103 and when entering another mobile network during communication with the mobile network 102 A similar effect can be realized by controlling the packet data relay apparatus.

  Further, when the branching of the IP packet realized by the present embodiment is canceled, the path change request may be made by storing the access IP address of the home network in the switching destination IP address.

  Furthermore, even when the home agent 115 and the mobile packet relay device 106 or the packet data relay device 110 are integrated, a system similar to the above can be configured. In this case, since the access IP address of the integrated network matches the home IP address, there is no need to establish a tunnel, and the effect of improving transmission efficiency can be obtained.

  In the above-described embodiment, the use of a network that can be connected in a wide band for moving image transmission is used as a network determination criterion. However, a connection destination can also be set based on preference information related to a user's communication line.

  In addition, when the terminal 101 starts communication when the standby process is in progress, the registration process for branching the packet transmission described in the above-described embodiment is performed, and the terminal 101 starts communication, the branch as illustrated in the latter half of the present embodiment. It is also possible to immediately execute the packet transmission.

  When communication is disconnected, the settings of all ports related to the communication can be changed so as not to branch. For this purpose, a route change request in which the IP address of the main relay device is stored as the switching destination address is output to all ports to which the terminal 101 branches when the service is disconnected, or the terminal corresponds to the IMS server. The port used for communication is stored, and when the communication is cut off, a route setting request for releasing all port branches is output from the IMS server to the mobile network packet relay device or packet data relay device.

  When the present embodiment is applied to Mobile IPv6, the mobile network packet relay device 106 or the packet data relay device 110 is set to MAP (Mobility Anchor Point) using the hierarchical Mobile IPv6, and these addresses are the care-of addresses 1102. It is possible to achieve the same effect as this embodiment by storing in the storage.

  In the above-described embodiment, the processing when the home network and the main relay device match is shown. However, the IMS server has a function of searching for the network to which the main relay device belongs, so that the home network and the main relay device can be searched. Even when the relay devices are different, it is possible to perform the same path switching as in the above-described embodiment. In this case, for example, when the terminal 101 registers Mobile IP, information (the IP address of the IMS server, the IP address of the relay device, the domain name, etc.) and the terminal ID are specified to the IMS server. When the terminal 101 outputs a route change request to the IMS server, the IMS server acquires information for identifying the main relay device from the registered information, and further, IMS that belongs to the same network as the main relay device from the information. The server IP address may be acquired from the user information storage device 113.

  Further, in the above-described embodiment, the route change method for the two networks before and after the change has been described. However, the information specifying the network to which all the relay devices used by the terminal 101 belong to the first IMS server 107 belongs. And the path change request is sent from the first IMS server 107 to the IMS servers of all the networks used by the terminal 101, and all the IMS servers that receive the signal of the second IMS server 111 of the above-described embodiment Similarly to the transfer change process, it is also possible to change the routes for three or more networks by performing the transfer change process of the relay devices belonging to the same network.

  In the above-described embodiment, the path switching is realized by simultaneously changing the settings of the relay apparatuses of a plurality of networks using the IMS server. However, the network relay apparatuses used before and after the path change And an interface for transmitting / receiving a route change request and a section for retrieving the IP address of the relay device of the network before the change from the network after the change, and a transfer change process similar to the present embodiment from the network before the change Even if it performs, the effect similar to the above-mentioned embodiment is acquired.

  In addition, an interface for path change is provided between the terminal 101 and the relay device, and all the relay devices in the connectable network have access IP addresses before and after the change, IP addresses of the transfer destination relay devices after the change, The same effect as described above can be obtained by outputting a route change request including the IP address of the main relay device from the terminal to the relay device and making the same change as in the above-described embodiment according to the request. .

  In this embodiment, the first relay device accessed after the terminal is turned on becomes the main relay device, but the main relay device can be changed by appropriately rewriting the contents of the terminal state management unit of each device. It is. In this case, the main relay device can be selected by the user or the network based on the distance and positional relationship with the terminal, and the bandwidth, delay, and throughput of the main relay device and other relay devices or the radio access network can be reduced. Based on this, a method of changing the connection destination to a network capable of communication most suitable for the application is also conceivable.

  As described above, in the present embodiment, the IMS server is provided with the terminal state management unit 402 and the transfer setting unit 403, and the IMS server of the transfer destination network sends the transfer setting request to the IMS server of the transfer source network. Output, and both the transfer source and transfer destination network relay devices store the IP addresses of the terminals in the transfer source and transfer destination networks in the terminal state management unit, and the packet relay unit 204 of the mobile network packet relay device 106 and the packet The packet relay unit 304 of the data relay device 110 and the IP distribution communication unit 505 of the terminal 101 specify the network of the packet data transmission destination for each port, and the communication quality can be improved without causing the home agent 116 to modify the existing home agent. The effect which cannot be obtained by the conventional system of improving is acquired.

  In addition, by providing an IMS server that outputs a route change request from the terminal 101 to the IMS server and changes the transfer setting of the relay device according to the route request, the user designates settings and operations of the terminal 101. The effect that the transmission path of packet data can be flexibly changed is obtained.

  Furthermore, by providing the IMS server with a terminal control unit 401 that controls the relay device from the IMS server, even if the information about the mutual address is not stored between the source and destination relay devices, the transmission path for each port. The effect that can be switched is obtained.

(Second Embodiment)
The system configuration of the interwork system according to the present embodiment is the same as that of the first embodiment described above. Therefore, the block diagram showing the system configuration of the interworking system of the present embodiment, the block diagram showing the internal configuration of the mobile network packet relay device, and the block diagram showing the internal configuration of the packet data relay device are also already referenced. 1, 2 and 3 are used. In the following, the operation continued from the final state of the operation of the system described in the first embodiment will be described.

  FIG. 18 is a sequence diagram showing the operation of the system according to the second embodiment of the present invention. In this sequence diagram, the operation continued from the final state of the operation of the system described in the first embodiment is shown. It is shown.

  The mobile network packet relay device 106 exchanges operation information such as traffic volume, number of connections, CPU usage rate, line usage rate, etc. handled by both relay devices at regular intervals with the packet data relay device 110 as an operation status exchange 1801. To do. The exchange of the operation state exchange 1801 may be performed when there are terminals that can access both the mobile network packet relay apparatus 106 and the packet data relay apparatus 110 at the same time.

  In the mobile network packet relay device 106, the GGSN connection setting unit 201 measures the state of the mobile network packet relay device 106 and outputs it to the packet data relay device 110 via the PDG / PDN communication unit 206. On the other hand, the operation information input from the packet data relay apparatus 110 is input to the PDG state management unit 203 via the PDG / PDN communication unit 206.

  In the packet data relay device 110, the PDG connection setting unit 301 measures the state of the packet data relay device 110 and outputs it to the mobile network packet relay device 106 via the GGSN / PDN communication unit 306. On the other hand, the operation information input from the mobile network packet relay device 106 is input to the SSGN state management unit 303 via the GGSN / PDN communication unit 306.

  In the packet data relay apparatus 110, “switch determination” (step S1802) is based on the operation information acquired in the operation state exchange 1801, and the PDG connection setting unit 301 acquires information from the GGSN state management unit 303 while checking the load level. The degree of congestion is determined, and switching determination processing is performed.

  The determination based on the operation information in the mobile network packet relay apparatus 106 is performed by the GGSN connection setting unit 201 acquiring information of the PDG state management unit 203. The mobile network packet relay device 106 determines the degree of load or the degree of congestion from the operation information of the mobile network packet relay device 106 and the packet data relay device 110.

  When the packet data relay apparatus 110 determines to switch, the packet data relay apparatus 110 outputs a MIP route change request 1803 to the home agent 115.

  Inside the packet data relay device 110, the PDG connection setting unit 301 extracts all the terminal ID, home IP address, and access IP address of the terminal using the home agent 115 from the terminal state management unit 302. For all these sets of data and each set, the IP address IPp of the packet data relay device 110 that is the output source of the request is stored in the main relay device IP address 706 (see FIG. 7). In addition, an MIP route change request 1803 is generated as the care-of address of all the terminals from which the IP address IPp of the packet data relay device 110 is extracted, and is output to the home agent 115. Thereafter, the packet is relayed according to the flow of FIG. 17 referred to in the first embodiment.

  Further, the packet data relay apparatus 110 instructs the main relay apparatus change 1804 to instruct “change main relay apparatus” to change the main relay apparatus of all terminals stored in the MIP route change request 1803 to the IP address IPp of the packet data relay apparatus 110. Is output to the mobile network packet relay device 106.

  In the mobile network packet relay device 106, when the terminal control unit 201 detects the main relay device change 1804 instructing “change main relay device”, the main relay device IP address 706 for all the terminal IDs included in the change is transmitted from IPg. Rewrite to IPp. When the processing is completed, the mobile network packet relay device 106 outputs a response indicating completion to the packet data relay device 110.

  When the MIP route change request 1803 is input, the home agent 115 rewrites the care-of address entries corresponding to all the corresponding terminals to the IP address IPp of the packet data relay device 110, and further the packet of the terminal corresponding to the rewritten entry. Change the transmission path.

  When the processing is completed, the home agent 115 outputs a route change confirmation 1805 to the packet data relay device 110.

  The audio data path changed as a result of the above processing is shown as 1806 (Audio), and the moving picture data path is shown as 1807 (Video). The time of this change is “time (d)”, and the data stored in the node at this time is shown in “(d)” of FIGS.

  In addition, in the main relay device change 1804 of the “main relay device change” process for the mobile network packet relay device 106, the timing for changing the main relay device is designated and synchronized with the timing for changing the main relay device of the packet data relay device 110. In addition to obtaining the same effect, the timing for changing the value between the mobile network packet relay device 106 and the packet data relay device 110 is shifted so that the IP packet is between the two. It is possible to avoid the inconvenient phenomenon of going back and forth and being discarded.

  In this embodiment, switching is realized by signal transmission / reception between the mobile network packet relay device 106 and the packet data relay device 110 on the network side, but instead of the MIP registration change request from the packet data relay device 110. Then, a notification for instructing or recommending a change of the main relay device (change of the care-of address) is given to a terminal that is a candidate for changing the main relay device. Furthermore, even if the terminal outputs a request to switch the care-of address to the home agent 115 in accordance with the notification, the same effect can be obtained, and the user can determine whether or not the change can be made. An interface between the mobile network packet relay device 106 and the packet data relay device 110 is not required, and the use of existing devices is facilitated.

  In the above-described embodiment, a method of switching all terminals belonging to the main relay apparatus to be switched at a time has been described. However, the number of terminals to be switched is reduced depending on the state of the terminal, the service being used, the necessary QoS parameters, and the like. It is also possible to do.

  As described above, in the present embodiment, the mobile network packet relay device 106 including the GGSN connection setting unit 201 that notifies the operation state of the mobile network packet relay device 106 and changes the main relay device, and the state of the packet data relay device 110 And the packet data relay device 110 including the PDG connection setting unit 301 that changes the main relay device, thereby switching traffic with the home agent 115 and avoiding an increase in network load and congestion. The effect that it becomes possible is acquired.

  Although the presently preferred embodiments of the present invention have been described above, it will be understood that various modifications can be made to the present embodiments and are within the true spirit and scope of the present invention. It is intended that the claims include all such variations.

  The wireless communication system according to the present invention has a function of allowing a user to select a communication network to be used according to the type and characteristics of transmission data, and is useful as a cooperative system using a plurality of communication networks. Further, the present invention can also be applied to uses such as failure avoidance for avoiding a situation where a communication carrier concentrates loads on some networks and nodes or congestion occurs.

  The present invention relates to a wireless communication system capable of optimally distributing communication of a terminal having a mobile communication and wireless LAN interface to both communication networks in a cooperative system of a mobile communication network and a wireless LAN network. It is about technology.

  In recent years, the construction of a communication system in which a cellular phone capable of communicating in a wide area and a public wireless LAN service capable of high-speed data communication in a relatively small area are linked (interworked) to complement each other has been studied. In such a communication system, for example, a terminal that can access both a mobile communication network of a mobile phone and a wireless LAN is used, and connection is made using a mobile network having a wide coverage area per base station during high-speed movement. On the other hand, it is possible to provide services such as high-speed access using a wireless LAN when moving at low speed or at rest.

  Interworking system is a 3GPP (3rd Generation Partnership Project), a new international standard for creating, distributing, and playing back multimedia over a third-generation high-speed wireless network. Scenario for accessing packet service of mobile network via WLAN The architecture that realizes is standardized. In the 3GPP standard, TR (Technical Report) 22.934 (TS (Technical Specification) 23.234 (3GPP system 23.234, “3GPP system to Wireless Local Network Network; Network Area Network); Describes the architecture and TS33.234 describes the authentication method.

  In these interwork system specifications, six scenarios from scenario 1 to 6 are defined depending on the form of interworking. For example, in scenario 3, a service that allows a terminal in a wireless LAN area to access a mobile network is defined. Scenario 4 defines a service that allows a terminal communication session to continue when the area of the wireless LAN and the mobile network changes during communication.

  As a method of realizing Scenario 4 with existing technology, Mobile IPv6 specified in RFC3344 (IETF RFC3344, "IP Mobility Support for IPv4") of IETF (Internet Engineering Task Force) and 3GPP standardized. A method of combining interworking systems is mentioned. The aim of this technology is to use Mobile IPv6 to conceal the movement of its own terminal from the communication partner's terminal, thereby continuing the communication session when moving between the wireless LAN network and the mobile communication network. It is in.

  FIG. 19 is a diagram for explaining an outline of a system configuration in which Mobile IPv6 and 3GPP interworking systems are combined. In FIG. 19, reference numeral 1901 denotes a terminal corresponding to a UE (User Equipment) in 3GPP. This terminal 1901 has an interface between a wireless LAN and a mobile phone, and is connected to a mobile (communication) network 1902 and a wireless LAN network 1903. The mobile network 1902 includes a mobile access network 1904, a packet control device 1905, and a mobile network packet relay device 1906. The wireless LAN network 1903 includes a WLAN access network 1908, a WLAN relay device, and a packet data relay device 1910. ing.

  A mobile access network 1904 provided in the mobile network 1902 can communicate with the mobile phone of the terminal 1901 and corresponds to a 3GPP UTRAN (Universal Terrestrial Radio Access Network). The packet control device 1905 performs GPRS (General Packet Radio Service) connection setting of the terminal 1901 and corresponds to a 3GPP SGSN (Serving GPRS Support Node). The mobile network packet relay apparatus 1906 corresponds to a 3GPP GGSN (Gateway GPRS Support Node), and relays packets between the mobile network 1902 and the public packet network 1911.

  The WLAN access network 1908 provides a wireless LAN connection to the terminal 1901 and corresponds to a 3GPP WLAN AN (Access Network). The WLAN relay device 1909 is connected to the WLAN access network 1908 and relays packets that can access the mobile network 1902. The packet data relay device 1910 relays the WLAN packet to the public packet network 1911. The public packet network 1911 is a communication network connected to the mobile network 1902 and the wireless LAN network 1903 and exchanging packets in the public, and corresponds to a 3GPP PDN.

  An IMS server 1907 that connects the mobile network packet relay apparatus 1906 and the packet data relay apparatus 1910 controls the IMS (IP Multimedia Core Network System) that supports real-time communication on a packet, etc., and 3GPP P-CSCF (Proxy) -Call Session Control Function). The user information storage device 1912 manages the connection status of the terminal 1901 and the like. This user information storage device 1912 is connected to the authentication system 1913. The authentication system 1913 relays an authentication signal with the user information storage device 1912 when performing authentication from the wireless LAN. The user information storage device 1912 corresponds to both 3GPP AAA Proxy / AAA Server.

  A home agent 1914 and a counter node 1915 are connected to the public packet network 1911. The home agent 1914 is a Mobile IP home agent, and the opposite node 1915 communicates with the terminal 1901.

  Hereinafter, an outline of the operation of the communication system shown in FIG. 19 will be described. When the terminal 1901 is powered on, the terminal 1901 first registers its own location and enters a standby state. At this time, the terminal 1901 acquires an access IP address for accessing the mobile network 1902, and registers the terminal 1901 and the mobile IP home IP address in the IMS server 1907.

  The access IP address IPa is an IP address used when the terminal 1901 is connected to the public packet network 1911. When the terminal 1901 uses the mobile network 1902, the access IP address is acquired via the mobile network packet relay device 1906. When the terminal 1901 uses the wireless LAN network 1903, the access IP address is acquired via the packet data relay device 1910. To do. In the example shown in FIG. 19, since the terminal 1901 is located in the area (M1) of the mobile network 1902, the access IP address IPa is acquired from the mobile network packet relay apparatus 1906.

  After acquiring the access IP address, the terminal 1901 performs location registration with the home agent 1914 using the access IP address IPa and the home IP address IPc. As a location registration method in this case, any of a method in which the terminal 1901 has a unique home IP address IPc and a method in which a functional element on the network side assigns the home IP address IPc may be used. After the location registration is completed, the terminal 1901 registers the ID (IMSI, International Mobile Subscriber Identifier) and the home IP address IPc of the terminal 1901 with the IMS server 1907. The above is the location registration process.

  When the location registration is completed, the terminal 1901 starts waiting for a call. Here, an example will be described in which after the standby start, the terminal 1901 makes a call by IMS and starts a videophone call combining voice and video. At this time, the audio and moving image streams pass through the home agent 1914 and the mobile network packet relay device 1906.

  When the terminal 1901 enters the wireless LAN area (L 1), packet transmission is performed to the terminal 1901 via the wireless LAN network 1903. Below, the outline | summary of the hand-over process which performs this switching is demonstrated. When the terminal 1901 enters the cell L1, the terminal 1901 obtains the access IP address IPb of the wireless LAN network 1903. Thereafter, the terminal 1901 performs Mobile IP registration with the home agent 1914 in order to communicate via the wireless LAN network 1903. The home agent 1914 changes the information related to the communication of the terminal 1901 so that the packet transmission path is via the packet data relay device 1910.

  When the above processing is performed, even if the terminal 1901 moves from the mobile network (M1) to the wireless LAN network (L1) during communication, the home IP address IPc used by the home agent 1914 when viewed from the opposite node 1915 changes. do not do. Further, since the home IP address IPc is registered, re-registration with the IMS server 1907 becomes unnecessary.

  Japanese Unexamined Patent Application Publication No. 2004-180311 discloses a method in a wireless communication network for connecting a terminal device and a router. This method uses the first network interface to establish a link layer connection with the first connection point, and then detects the second connection point using the second network interface, The connection point and the link layer connection are established, the compatibility between the connection router connected to the second connection point and the terminal device is determined, and the terminal device and the connection router are connected.

  FIG. 20 is a conceptual diagram for explaining the method disclosed in Japanese Patent Application Laid-Open No. 2004-180311. In the system shown in FIG. 20, the mobile network 2002 and the wireless LAN network 2003 are linked in the same way as the system shown in FIG. A mobile network packet relay device 2004 is disposed in the mobile network 2002, and an LMA 2005 is disposed in the wireless LAN network 2003. Note that wireless-related functional elements such as a radio network controller (RNC) are not shown. The basic operations of the terminal 2001, the mobile network 2002, and the wireless LAN network 2003 shown in FIG. 20 are the same as those of the system of FIG. 19, and the public packet network 2007 and the opposite node 2008 are also connected to the public packet network 1901 of FIG. Since it is the same as that of the node 1915, redundant description is omitted.

  Similar to the mobile network packet relay device 1906 illustrated in FIG. 19, the mobile network packet relay device 2004 relays packets and manages the connection of the terminal 2001. LMA 2005 (LMA is an abbreviation of Local Mobility Agent) relays packets between the mobile network 2002 and the wireless LAN network 2003, and assigns an access IP address according to a request from the terminal 2001. ISP 2006 (ISP stands for Internet Service Provider) provides connection to the public packet network 2007 and assigns an IP address to the terminal 2001.

  In the system shown in FIG. 20, when the terminal 2001 is turned on, the connection of the terminal 2001 to the public packet network 2007 is established. The terminal 2001 acquires an IP address IP-mt by using the GPRS procedure, and creates connection information called “Secondary PDP context” for the GGSN. This “Secondary PDP context” is GPRS connection information such as QoS, but relay information and the like can also be used for a wireless LAN.

  Next, when the terminal 2001 enters the area of the wireless LAN network 2003, the terminal 2001 acquires an access IP address in the wireless LAN network 2003 and performs Mobile IP registration processing on the LMA 2005. The LMA 2005 registers with the mobile network packet relay apparatus 2004 using GPRS. As a result, the connection information of the terminal 2001 is associated with the LMA 2005 of the wireless LAN network 2003, and the packet of the terminal 2001 passes through the LMA 2005.

  In the system shown in FIG. 20, both the mobile network 2002 and the wireless LAN 2003 are routed simultaneously. As a result, when traffic is concentrated on either network, the load between the networks can be distributed.

  As described above, in the specification of the interwork system as shown in FIG. 19, six scenarios from scenario 1 to 6 are defined depending on the form of the interwork. These scenarios stipulate a service that allows a terminal in a wireless LAN area to access a mobile network and a service in which a terminal service continues even when the area of the wireless LAN and the mobile network changes during communication.

  However, in these services, since a terminal and a communication path have a one-to-one correspondence, a network suitable for service data transmission cannot be selected for each service used by the terminal. When the load is concentrated on one of the mobile network 1902 and the wireless LAN network 1903, the user connected to the network on which the load is concentrated is moved to the other network to distribute the load. There is a problem that it cannot be planned.

  On the other hand, in the interwork system shown in FIG. 20, the relationship between the mobile network and the wireless LAN network must be fixed. Specifically, the LMA 2005 needs to hold the address of the mobile network packet relay device 2004 in advance in order to transfer the registration request from the terminal 2001 to the mobile network packet relay device 2004. Also, since the mobile network packet relay device 2004 manages the wireless LAN network 2003 using GPRS connection information, the LMA 2005 is not an IETF standard Mobile IP (IETF RFC3344, “IP Mobility Support for IPv4”). It is necessary to implement GPRS, which is a limited 3GPP standard protocol. Due to such restrictions, when the system shown in FIG. 20 is used, the number of interconnection destinations is limited.

  The present invention has been made in view of such problems, and an object of the present invention is to execute packet distribution processing in both the mobile network and the wireless LAN network, and to switch the connection due to factors on the network side. By using IMS when setting the packet distribution, it is possible to appropriately set the packet distribution processing method even when an unknown network becomes an interconnection target.

  The wireless communication system of the present invention includes a public packet network, a plurality of wireless communication networks each provided with a relay device, a terminal capable of packet connection with the plurality of wireless communication networks, and the public packet network via the public packet network. A counter node that performs packet communication with the terminal, and a router that manages a destination of the terminal that changes according to movement of the terminal, the terminal including a relay device that relays a packet transmitted from the counter node to the terminal The information specifying the relay device is set in the main relay device selected from the plurality of relay devices, and the router sends the packet addressed to the terminal input from the opposite node to the main relay device. The main relay device outputs the packet addressed to the terminal to the IP address of the forwarding device specified for each port number of the terminal, and the relay device is input from the main relay device. Outputting a packet addressed to the terminal to the terminal, the terminal is configured to output a packet addressed to the remote node to the IP address of the transfer destination relay apparatus, which is designated for each port number.

  By adopting such a configuration, it is possible to perform appropriate packet distribution processing even when the destination network of packet data is designated for each port and an unknown network becomes an interconnection target.

  In the above wireless communication system, the main network IMS server that performs call control of packet calls belonging to the wireless communication network of the main network provided with the main relay device, and a packet for each wireless communication network in the area other than the main network A visited network IMS server that performs call control of the call, and the visited network IMS server sets a transfer setting for relaying a packet of a designated port number to a relay device provided in the visited network The processing is executed, and a route change request storing a set of the terminal identifier, the port number, and the IP address of the forwarding destination relay device is output to the main network IMS server, and the main network IMS server responds to the route change request, A transfer setting process for changing the transfer destination of the packet of the designated port number to the transfer destination relay device is executed on the main relay device.

  With this configuration, it is possible to flexibly change the packet data transmission path by specifying the terminal settings and operations by the user, and information about each other's address is stored between the source and destination relay devices. Even if it is not done, the effect is obtained that the transmission path can be switched for each port.

  In the above wireless communication system, the terminal is configured to be able to output a route change request to the main network IMS server or the visited network IMS server, and the visited network IMS server responds to the route change request from the terminal. The transfer setting process is executed.

  With such a configuration, it is possible to perform packet transfer processing in response to a route change request input from the terminal side.

  In the above wireless communication system, the relay device setting unit that outputs the operation information of one relay device selected from the plurality of relay devices, and the operation information output from another relay device other than the one relay device. A relay device that compares the operation information of the one relay device with the operation information of another relay device, and based on the result, the main relay device for switching the main relay device. The relay device change process is executed for another relay device, and the other relay device executes the change process in which the main relay device corresponding to the terminal designated based on the main relay device change process is set as one relay device. Then, the one relay device is configured to output a MIP route change request for registering the address of the one relay device as a care-of address with the change of the main relay device to the router.

  With such a configuration, it is possible to perform packet transfer processing in response to a request from the wireless communication network side, and it is possible to avoid an increase in load and congestion on the wireless communication network side.

  The wireless communication method of the present invention includes steps necessary for wireless communication in the system.

  With this configuration, packet distribution processing is executed in both the mobile network and the wireless LAN network, and even when an unknown network becomes an interconnection target, the packet distribution processing method is set appropriately. Can be made possible.

  The wireless communication system of the present invention performs packet distribution processing in both the mobile network and the wireless LAN network, and even when an unknown network becomes an interconnection target, the packet distribution processing method is appropriately performed. Setting is possible.

  The wireless communication system of the present invention has a function of allowing a user to select a communication network to be used according to the type and characteristics of transmission data, and is useful as a cooperative system using a plurality of communication networks. Further, the present invention can also be applied to uses such as failure avoidance for avoiding a situation where a communication carrier concentrates loads on some networks and nodes or congestion occurs.

  As described below, there are other aspects of the present invention. Accordingly, this disclosure is intended to provide some aspects of the invention and is not intended to limit the scope of the claimed invention.

  The wireless communication system of the present invention will be described below with reference to the drawings. However, the following detailed description and the accompanying drawings do not limit the invention. The scope of the invention is defined by the appended claims.

(First embodiment)
FIG. 1 is a block diagram showing a system configuration of an interworking system according to the first embodiment of the present invention. In FIG. 1, the terminal 101a in the area M1 and the terminal 101b in the area L1 are terminals having the same configuration, and both may be collectively referred to as the terminal 101. Terminal 101 in the present embodiment includes an interface for communicating with mobile network 102 and wireless LAN network 103. The terminal 101 corresponds to a UE (User Equipment) in 3GPP when communicating with the mobile network 102.

  In the example shown in FIG. 1, the terminal 101a is located in the area (M1) of the mobile network 102, and the terminal 101b is located in the area (L1) where both the mobile network 102 and the wireless LAN network 103 can be accessed. is doing. In the following description of the present embodiment, processing when the terminal 101 initially registers its position in the terminal 101a and then starts communication and moves to the position of the terminal 101b will be described.

  The mobile network 102 is a (communication) network that complies with mobile communication standards such as GSM, GPRS, and W-CDMA. In the present embodiment, it is assumed that mobile network 102 is the home network of terminal 101. Here, the home network means a network with which the user of the terminal 101 is contracted, and the visited network means a network to which a cell at a location where the terminal 101 exists belongs.

  The mobile network 102 includes a mobile access network 104, a packet control device 105, and a mobile network packet relay device 106. The mobile access network 104 has a radio interface of the mobile network 102 and transmits data of the mobile network 102 and corresponds to 3GPP UTRAN. The packet control device 105 performs GPRS connection setting of the terminal 101, and corresponds to 3GPP SGSN. The mobile network packet relay device 106 corresponds to a 3GPP GGSN and relays packets between the mobile network 102 and the public packet network 112.

  The wireless LAN network 103 has a wireless LAN interface such as IEEE802.11 / 11a / 11b / 11g / 11n and HIPERLAN and transmits packets. The wireless LAN network 103 includes a WLAN access network 108, a WLAN relay device 109, and a packet data relay device 110.

  The WLAN access network 108 provides a terminal with a wireless LAN connection, and corresponds to a 3GPP WLAN AN (Access Network). The WLAN relay device 109 is connected to the WLAN access network 108 and relays a packet accessible to the mobile network 102. The packet data relay device 110 relays the wireless LAN packet to the public packet network 112.

  The first IMS server 107 performs IMS call control processing related to terminals existing in the mobile network 102. The first IMS server 107 corresponds to an S-CSCF (Serving-CSCF) of 3GPP. The second IMS server 111 connected to the first IMS server 107 relays a signal related to IMS call control processing related to a terminal existing in the wireless LAN network 103, and corresponds to a 3GPP P-CSCF. The first IMS server 107 and the second IMS server 111 may be collectively referred to simply as “IMS server”.

  The user information storage device 113 manages the connection state of the terminal 101 and corresponds to a 3GPP HLR (Home Location Register) or HSS (Home Subscriber Server). The authentication system 114 connected to the user information storage device 113 relays an authentication signal with the user information storage device 113 when performing authentication from the wireless LAN. The authentication system 114 corresponds to one or both of 3GPP AAA Proxy / AAA Server.

  The public packet network 112 is connected to the mobile network 102 and the wireless LAN network 103. The public packet network 112 is a network for exchanging packets in the public, and corresponds to a 3GPP PDN (Packet Data Network). The public packet network 112 is connected to a home agent 115 that is a router that supports movement of the mobile node and an opposite node 116. The home agent 115 is a Mobile IP home agent, and the opposite node 116 communicates with the terminal 101.

  FIG. 2 is a block diagram showing an internal configuration of the mobile network packet relay device 106. In this figure, a GGSN connection setting unit 201 performs connection setting for the terminal 101 that uses the mobile network packet relay apparatus 106. The terminal status management unit 202 manages the connection status related to the terminal 101 using the mobile network packet relay device 106. The PDG state management unit 203 acquires and manages an operation state such as a load of the packet data relay apparatus 110. The packet relay unit 204 inputs and outputs packet data between the packet control device 105, the packet data relay device 110, and the public packet network 112 and the mobile network packet relay device 106.

  The SGSN communication unit 205 performs protocol processing with the packet control device 105 and inputs / outputs communication data. The PDG / PDN communication unit 206 inputs and outputs packets between the packet data relay device 110 and the public packet network 112. In the present embodiment, it is assumed that these and mobile network packet relay apparatus 106 are both connected via IP. Further, the IMS communication unit 207 performs communication of call control data between the mobile network packet relay device 106 and the “IMS server”.

  FIG. 3 is a block diagram showing an internal configuration of the packet data relay apparatus 110. In FIG. 3, the PDG connection setting unit 301 performs connection settings regarding the terminal 101 that uses the packet data relay apparatus 110. The terminal state management unit 302 manages the connection state regarding the terminal 101 that uses the packet data relay device 110. The GGSN state management unit 303 performs protocol processing with the mobile network packet relay device 106 and input / output of communication data. The packet relay unit 304 inputs and outputs packet data between the WLAN relay device 109, the mobile network packet relay device 106, and the public packet network 112 and the packet data relay device 110.

  The WAG communication unit 305 performs protocol processing with the WLAN relay device 109 and input / output of communication data. The GGSN / PDN communication unit 306 inputs and outputs packets between the mobile network packet relay device 106 and the public packet network 112. It is assumed that the mobile network packet relay device 106, the public packet network 112, and the packet data relay device 110 are all connected via IP. Then, the IMS communication unit 307 performs call control data communication between the mobile network packet relay device 106 and the IMS server.

  FIG. 4 is a block diagram showing an internal configuration of the IMS server. In this figure, the terminal control unit 401 performs connection settings relating to the terminal 101 using the “IMS server”. The terminal state management unit 402 manages the state of call control related to the terminal 101 using the IMS server. The transfer setting unit 403 performs setting for transferring the call control message according to the terminal 101. The IP communication unit 404 performs IP transmission and Mobile IP processing.

  The packet network communication unit 405 communicates with the public packet network 112. The IMS communication unit 406 communicates with another “IMS server”. The GGSN / PDG communication unit 407 inputs and outputs packets between the mobile network packet relay device 106 and the packet data relay device 110. It is assumed that the mobile network packet relay device 106, the packet data relay device 110, and the IMS server are all connected via IP.

  FIG. 5 is a block diagram showing an internal configuration of the terminal 101. In FIG. 5, a terminal call control unit 501 performs call control related to the terminal 101, generates a message to the IMS server, and has a function of IMS and SIP protocol processing. The terminal state management unit 502 manages various states related to the terminal 101. The path control unit 503 determines an appropriate transmission path according to the application or connection. The IP communication unit 504 performs IP communication for the terminal 101. The IP distribution communication unit 505 refers to the terminal state management unit 502, distributes packets according to the type of network, and determines a packet communication destination.

  The GPRS communication unit 506 performs a protocol process related to GPRS. The mobile access network communication unit 507 communicates with the mobile access network 104 and performs radio control. The WLAN access IP communication unit 508 communicates with the packet data relay device 110 using the access IP address of the wireless LAN network. The WLAN communication unit 509 communicates with the WLAN access network 108.

  6 is a field diagram showing data of the terminal status management unit of the terminal 101, FIG. 7 is a field diagram showing data of the terminal status management unit of the mobile network packet relay device 106, and FIG. 8 is a terminal status management of the packet data relay device 110. FIG. 9 is a field diagram showing data of the terminal status management unit of the first IMS server 107, FIG. 10 is a field diagram showing data of the terminal status management unit of the second IMS server 111, and FIG. It is a field diagram which shows the data of the terminal state management part of the agent 115. FIG.

Hereinafter, the meanings of addresses and the like shown in the field diagrams of FIGS. 6 to 11 will be described.
“Terminal ID” (601, 701, 801, 901, 1001, 1101) is an identifier for uniquely identifying a terminal. As this terminal ID, for example, IMSI, NAI (Network Access Identifier), SIP URI, SIP URL, or the like can be used.

  “Access IP address” (605, 606, 702, 802) is an IP address used when the terminal 101 accesses the mobile network 102 or the wireless LAN network 103. In the present embodiment, the home agent 115 exists outside the mobile network 102 and the wireless LAN network 103. Therefore, it is not guaranteed that the home IP address (described later) handled by the home agent 115 can be routed in both networks. When the terminal 101 performs access, it is necessary to obtain an access IP address that can be routed within the access network from the network that performs access.

  “Home IP address” (607, 703, 803, 1103) is an IP address used when the terminal 101 accesses the mobile network 102 and the outside of the wireless LAN network 103. In the present embodiment, in order to provide mobility of the terminal 101 for both the mobile network 102 and the wireless LAN network 103, a home IP address is used when accessing the outside. In this embodiment, it is assumed that terminal 101 has a home IP address in advance, but the same effect can be obtained even when the home IP address is acquired at the start of access.

  “Used port number” (609, 704, 804) is a port number such as TCP, UDP, SCTP, etc., used by the terminal 101 for transmission of the communication service, and is a transmission path for transmission to or from the same address. It is a number for distinguishing. In the field diagram, only the examples of the port numbers “Pa” and “Pv” are shown, but the value of “default” can also be specified to indicate the specification for other port numbers. For example, if “default” is specified in addition to “Pa” and “Pv”, it indicates all port numbers other than “Pa” and “Pv”.

  In FIG. 6, “terminal state” 602 indicates the communication state of the terminal, and has three types of states: “stop”, “standby”, and “in communication”. “GPRS connection information” 603 is connection information related to GPRS and corresponds to the PDP context of 3GPP TS 23.060. “WLAN connection information” 604 is information stored for connection to the wireless LAN network 103. Examples of the “WLAN connection information” include a WEP key for connecting to the WLAN access network 108, an ESS-ID, an authentication method, an authentication ID, a password, and the like, and an access IP address assigned to the terminal after connection. “IMS server address” 608 is the address of the IMS server used by the terminal. “Used network relay device IP address” 610 is an IP address of a relay device of either the mobile network 102 or the wireless LAN network 103 used for packet communication from the terminal 101 to the home agent 115. The “used network relay device IP address” 610 is assigned to each “used port number” 609.

  7 and 8, the forwarding destination relay device IP address (705, 805) indicates an address that is a transmission destination of a downlink packet (addressed to the terminal 101) of the corresponding use port. The transfer destination relay device IP address (705, 805) is assigned to each used port number (704, 804). The main relay device IP address (706, 806) indicates the IP address of the main relay device. Note that the main relay device is a relay device to which a care-of address registered in the home agent is assigned for each terminal, and specifically, a mobile network packet relay device or a packet data relay device. GPRS connection information (707, 807) is connection information related to GPRS and corresponds to a PDP context in 3GPP.

  9 and 10, the terminal IP address (902, 1002) is the IP address of the terminal 101. The home server IP address (903, 1003) is the IP address of the IMS server of the home network of the terminal 101. In the present embodiment, the home network of terminal 101 is assumed to be mobile network 102, and wireless LAN network 103 is the visited network of terminal 101.

  In FIG. 11, a care-of address 1102 is a care-of address used in Mobile IP. In the case of Mobile IPv4 assumed in the present embodiment, the address of a relay device that is a Foreign Agent (FA) is used.

  Below, with reference to FIGS. 12-17, the operation | movement of the system in this Embodiment is demonstrated.

  FIG. 12 is a sequence diagram when the terminal 101 is located in the cell M1 and becomes the terminal 101a, and FIG. 13 is a sequence diagram when the terminal 101a moves to the cell L1 and becomes the terminal 101b.

  FIG. 14 is a state transition diagram of terminal 101 in the present embodiment. As shown in FIG. 14, the terminal 101 has three states of “stop” 1401, “waiting” 1402, and “communication” 1403 depending on power on / off, stay area, and communication start / completion. Take. The state of the terminal 101 is stored in the terminal state 602 field of the terminal state management unit 502.

  FIG. 15 is a flowchart for explaining the operation of terminal 101 at the time of location registration in this embodiment, FIG. 16 is a flowchart for explaining the operation of terminal 101 during communication, and FIG. 17 is a mobile network packet. It is a flowchart for demonstrating the operation | movement of the packet transfer of a relay apparatus or a packet data relay apparatus.

  A sequence when the terminal 101 is located in the cell M1 and becomes the terminal 101a will be described with reference to FIG. A state 1201 indicates that the terminal 101a is “stopped” 1401 (FIG. 14). When the terminal 101a is powered on by the user, the powered terminal 101a outputs GPRS location registration / user information registration 1202. In the process of outputting the GPRS location registration / user information registration 1202, the terminal 101a performs the processes from step S1501 to step S1503 in FIG. That is, first, a connectable network is detected (step S1501). Here, it is assumed that the terminal 101a can communicate only with the mobile network 102. Next, the type of the detected network is determined (step S1502). If it is determined that the detected network is a mobile network, the process proceeds to the GPRS connection process (step S1503), and the position M1 of the terminal ID1 is registered in the mobile packet relay apparatus 106 by this process.

  In this GPRS connection process (step S1503), the terminal 101a notifies the mobile network packet relay device 106 that the registration is registration of the first network after power-on. The mobile network packet relay device 106 registers its own address IPg as the main relay device IP address of the terminal 101a. The terminal 101a acquires the access IP address IPa on the mobile network 102 side from the mobile packet relay apparatus 106. At this time, the following processing is performed inside the terminal 101a.

  When the power of the terminal 101a is turned on, the GPRS communication unit 506 of the terminal 101a starts a GPRS location registration process, outputs a request to the packet control device 105, and inputs a response. The mobile access network communication unit 507 Do through. In the terminal 101a, the GPRS communication unit 506 performs packet communication with the mobile network packet relay apparatus 106 of the mobile network 102. In the GPRS location registration / user information registration 1202 process, the GPRS communication unit 506 is basically used to perform the same process as the GPRS protocol. Location registration processing performed between the terminal 101a and the packet control device 105 includes ATTACH processing and authentication processing for performing location registration. In 3GPP TS 23.060, ATTACH Request / Response / Accept / Complete, Identity Request / Response. The process is executed according to the IMEI Check procedure.

  When the GPRS location registration / user information registration 1202 is input, the packet control device 105 performs GPRS connection setting. In this GPRS connection setting, the packet control device 105 creates (primary) GPRS connection information (PDP context in 3GPP) for the packet control device 105 corresponding to the terminal 101, and starts managing the position of the terminal 101 in the mobile network 103 To do. Further, in GPRS connection setup, the packet control device 105 performs location update processing (Location Update Request / Response in 3GPP), creation processing of (primary) GPRS connection information to the mobile network packet relay device 106 (Create PDP Context in 3GPP). (Request / Response) and location update processing (routing area update in 3GPP) to the user information storage device 113 is performed.

  When the GPRS location registration / user information registration 1202 is input, the mobile network packet relay device 106 creates (secondary) GPRS connection information (Secondary PDP context in 3GPP) and passes the access IP address IPa to the terminal 101a. . Then, the terminal 101 a stores the access IP address IPa for the mobile network 102 in the terminal state management unit 502. In the following, when simply describing GPRS connection information, it means GPRS connection information for mobile network packet relay devices.

  The access IP address IPa is assigned by a node outside the mobile network packet relay device 106 such as the public packet network 112 and transmitted to the terminal 101a via the mobile network packet relay device 106.

  At this time, in the mobile network packet relay device 106, first, a request from the terminal 101 a is input to the SGSN communication unit 205 via the packet control device 105. Since the request from the terminal 101a is related to GPRS location registration, the GGSN connection setting unit 201 creates GPRS connection information for the mobile network packet relay device corresponding to the terminal 101, and the terminal state management unit 202 Is stored as GPRS connection information 707.

  Further, since the mobile network packet relay device 106 is the first relay device to which the terminal 101 a is connected, the mobile network packet relay device 106 stores the IP address IPg of the mobile network packet relay device 106 as the main relay device IP address 707. The mobile network packet relay apparatus 106 stores the access IP address IPa in 702 as the access IP address. After creating the GPRS connection information, the GGSN connection setting unit 201 generates a response and outputs the response to the packet control apparatus 105 via the SGSN communication unit 205.

  Further, the packet control device 105 receives the GPRS location registration / user information registration 1202 and registers the terminal ID and the connected location (cell M1) in the user information storage device 113. Here, Update Location / Ack and Insert Subscriber Data message in 3GPP are used. As a result of the above processing, communication by GPRS of the terminal 101a becomes possible.

  The terminal 101a outputs the MIP registration 1203. Before outputting the MIP registration 1203, the terminal 101a registers the access IP address IPa of the mobile network 102 together with the home IP address as a care-of address in the home agent 115 in the Mobile IP setting process (step S1506). Before executing Step S1506, the terminal 101a separately acquires the IP address of the home agent 115 and the home IP address of the terminal 101a and stores them in the terminal state management unit 502. For example, the terminal 101a may always hold the home IP address in the terminal state management unit 502, or a method of separately authenticating with the service provider of the home agent and distributing it when the authentication is completed is possible.

  In the terminal 101a, when GPRS communication setting by the GPRS communication unit 506 is completed, the access IP address is notified to the terminal call control unit 501 via the IP distribution communication unit 505 and the IP communication unit 504. The terminal call control unit 501 registers the access IP address IPa in the terminal state management unit 502 together with the terminal 101a (terminal ID is ID1). When this registration is completed, the terminal call control unit 501 creates a MIP registration 1203 that is a request for registering the terminal 101a in the home agent 115, and the IP communication unit 504 and the IP distribution communication unit 505 send an IP packet for an external network. The MIP registration 1203 is output to the mobile access network 104 via the GPRS communication unit 506 and the mobile access network communication unit 507. In the subsequent processing, all IP packets passing through the mobile network 102 are input / output using this route.

  As shown in FIG. 12, the MIP registration 1203 is input to the home agent 115 via the mobile access network 104, the packet control device 105, the mobile network packet relay device 106, and the public packet network 112. The MIP registration 1203 is a signal including Mobile IP Registration Request / Reply.

  The home agent 115 registers the access IP address IPa as the terminal ID 1101 ID1 and the access IP address 1102, and registers the home IP address IPc as the home IP address 1103 in association with the access address IPa. After this registration is completed, the home agent 115 outputs a response indicating registration success to the terminal 101a. When this response is input, in the terminal 101a, the terminal call control unit 501 registers a set of ID1 that is the terminal ID of the terminal 101a and the home IP address IPc in the terminal state management unit 502.

  IMS server search / SIP registration 1204 is a signal that the terminal 101a outputs to the first IMS server. Before the IMS server search / SIP registration 1204 is output, the terminal 101a performs the SIP setting process S1507 when the Mobile IP process is completed. In IMS server search / SIP registration 1204, the terminal 101 a searches for an IMS server related to the mobile network 102, and stores the IP address in the terminal state management unit 502 when the IMS server is detected. At this time, the address IPs of the first IMS server 107 that is an IMS server that controls the terminals under the mobile network 102 is acquired from the mobile network 102.

  Note that 3GPP TS23.228 (3GPP TS23.228, “IP Multimedia Subsystem (IMS); Stage 2”) describing the IMS specifications is linked with the DHCP server of the mobile network 102 and the DNS server in cooperation with the IP of the IMS server. A mechanism for notifying the address to the terminal 101a is shown. There is also a method for obtaining the IP address of the IMS server from the mobile packet relay device 106 or the packet control device 105.

  The terminal 101 a outputs an IMS server search / SIP registration 1204 to the first IMS server 107. This signal corresponds to IETF SIP Registration. When the IMS server search / SIP registration 1204 is output, the following processing is performed inside the terminal 101a.

  When the terminal call control unit 501 acquires the IP address IPs of the first IMS server 107, the terminal call control unit 501 creates a SIP registration request and outputs it to the mobile network 102 in order to perform registration processing with the first IMS server 107. When the IMS server search / SIP registration 1204 is input by the terminal 101a, the terminal 101a executes the SIP registration processing to the first IMS server 107, and the user ID and the home IP address IPc of the terminal 101a are stored in the user information storage device 113. be registered. In TS23.228, “public user identity” (telephone number, RFC URI 3261 SIP URI or RFC2806 tel URL) or “private user identity” (NAI form is used by Cx-Put / Cx-Pull. "S-CSCF name" is output.

  In the first IMS server 107, first, the GGSN / PDG communication unit 407 performs IP protocol processing in the IP communication unit 404 up to the MAC layer (Media Access Control layer) which is a part of the data link layer, and the IMS server. When the search / SIP registration 1204 is input, the terminal control unit 401 analyzes the message. In this case, since it is SIP registration for the home network, the terminal control unit 401 sets ID1 and home IP address IPc as a set of the terminal ID 901, home IP address 902, and home server IP address 903 input to the terminal state management unit 402, respectively. The IP address IPs of the first IMS server 107 is registered. Thereafter, a response indicating registration completion is output to the terminal 101b via the IP communication unit 404 and the GGSN / PDG communication unit 407. In the terminal 101a, the IP address IPs of the first IMS server 107 is registered in the IMS server IP address 608 of the terminal state management unit 502.

  When the SIP registration processing of IMS server search / SIP registration 1204 is completed in the terminal 101a, the series of processing illustrated in FIG. 15 is completed, and the terminal 101a is in the “waiting” state 1402 (state 1205) (FIG. 14). It becomes. Here, the terminal call control unit 501 in the terminal 101a changes the state in the terminal state management unit 502 to “standby”.

  When the SIP registration is completed, in the SIP call processing 1206, the terminal 101a uses the first IMS server 107 to make a SIP call to the opposite node (ID2). The transmission starts with a SIP INVITE message, and “Offer”, “Reservation”, “Ringing”, “OK”, and “ACK” messages are transmitted and received. These signals are relayed by the mobile network 102 and the first IMS server 107 and output to the opposite node.

  When the series of processing is completed, the terminal 101a starts outputting the terminal data stream (signal 1207) to the acquired IP address of the opposite node as shown in FIG. Further, the terminal 101b stores in the terminal state management unit 502 that both the voice use port Pa and the video use port Pv are via the mobile network packet relay device 106.

  When the terminal 101a completes the output of the SIP call processing 1206, the terminal 101a enters a “communication” state 1403 (FIG. 14) in a state 1208. Here, the terminal call control unit 501 in the terminal 101 a changes the state in the terminal state management unit 502 to “in communication” 1403. This time is “time (a)”, and data stored in the node at this time is shown in “(a)” in FIGS.

  Next, the operation of the system of this embodiment when the terminal 101a moves to the cell L1 and becomes the terminal 101b will be described using the sequence diagram of FIG. 13 and the flowchart of FIG. FIG. 13 shows a sequence continued from FIG.

  FIG. 16 is a flowchart for explaining processing from network detection to network selection in the “in communication” state 1403. At the first time point in FIG. 13, the terminal 101a moves to the cell L1 and becomes the terminal 101b in the last cell L1 entry 1209 in FIG. The terminal 101b detects the wireless LAN network 103 as a connectable network through “connectable network detection / connection process” (step S1601) in FIG. 16, and this is referred to as “network A” in process S1601. Execute the connection process.

  In the WLAN connection setting 1301 illustrated in FIG. 13, the terminal 101 b performs the WLAN connection setting for the entered wireless LAN network 103. First, the WLAN access network 108 that has detected the terminal 101 b performs WLAN connection setting, and issues a local IP address IPb that the terminal 101 b uses when connecting to the wireless LAN access network 108. In the terminal 101b, the WLAN communication unit 509 performs physical layer and MAC layer communication processing with the WLAN access network. The WLAN communication unit 509 receives a beacon output from the WLAN access network 108 or detects an access point of the WLAN access network 108 and performs connection processing of the wireless LAN network 103 and authentication processing as necessary.

  Here, if the standard of the wireless interface used by the wireless LAN network 103 is IEEE802.11, Beacon and Probe Request / Response are used for the connection process, and an Authentication Request / Response message is used for the authentication process. In the authentication process, the NAI of the terminal can be used in addition to the terminal ID.

  After the connection process to the MAC layer, the WLAN communication unit 509 acquires the local IP address IPl in the wireless LAN network 103. The local IP address may be acquired simultaneously with the authentication process.

  Inside the terminal 101b, the WLAN communication unit 509 outputs the terminal ID by an authentication procedure determined by the wireless LAN network 103, and the WLAN access network 108 performs authentication. As a result of authentication, if it is determined that the WLAN access network 108 can be accessed with the terminal ID of the terminal 101b, the WLAN access network 108 responds and inputs the local IP address IPl to the WLAN communication unit 509. Further, the local IP address IPl is stored as the WLAN connection information 604 in the terminal state management unit 502.

  When connection to the wireless LAN network 103 becomes possible, the terminal 103b performs a series of processes shown in FIG. 16, that is, a process for selecting a network to be connected during communication. In this case, a determination is made to change the moving image use port Pv from the mobile network 102 to the wireless LAN network 103.

  The terminal 101 b obtains the access IP address IPb of the wireless LAN network 103 via the packet data relay device 110 and stores it as the access IP address 606 for the wireless LAN network 103 in the terminal state management unit 502. The access IP address IPb is a remote IP address in the interworking use specified by 3GPP TS23.234. Thereafter, the terminal 101b can communicate via the packet data relay device 110 and the WLAN relay device 109.

  Inside the terminal 101b, the WLAN access IP communication unit 508 selects the wireless LAN network 103 accessible from the WLAN access network, and outputs an authentication request including the terminal ID ID1 to the authentication system 114. If the terminal 101b can communicate with the wireless LAN network 103, an authentication response indicating permission is input to the terminal 101b. Thereafter, a setting process for establishing a tunnel between the terminal 101b and the packet data relay apparatus 110 is performed, and communication is started. During this process, the WLAN connection information 604 is stored in the terminal state management unit 502.

  After the above process, when the terminal 101b communicates with the wireless LAN network 103, the WLAN access IP communication unit 508 performs an encapsulation process for communicating with the packet data relay apparatus 110 inside the terminal 101b. The WLAN communication unit 509 performs processing of the physical layer and the MAC layer of the wireless LAN and encapsulation processing using a local IP address in the wireless LAN network 103. In the following, when it is described that “the terminal 101b communicates with the wireless LAN network 103”, it is assumed that these processes are performed in the terminal 101b.

  The terminal 101b searches for the IP address IPp of the packet data relay apparatus using a DNS server (not shown). Inside the terminal 101b, the WLAN access IP communication unit 508 acquires the IP address IPp of the packet data relay apparatus 110. As a result, the terminal 101b and the wireless LAN network 103 can be connected, and step S1601 is completed.

  In “acquiring a network during communication” (step S1602), the terminal 101b acquires the mobile network 102, which is a network during communication, and sets this as “network B”. Then, in “network A ≠ network B” (step S1603), which is a process for determining whether or not the networks match, network A that can be connected is compared with network A that is in communication. Here, since the network B that is in communication is different from the network A that can be connected, the process proceeds to “Extraction of uncommunication & connectable network” (step S1604). In the network comparison process in step S1603, the IP address IPg of the mobile network packet relay device 106 of the mobile network 102 is acquired as the address of the relay device being used, and the packet data relay that is the relay device of the wireless LAN network 103 is acquired. The IP address corresponding to the mobile network 102 and the IPb corresponding to the wireless LAN network 103 are determined to be different from the IP address IPp of the device 110 or assigned to each network connected to the terminal 101. May be determined to be different.

  In step S1604, a network that is not communicating and can be connected is extracted, and is set as “network C”. At this time, in the terminal 101b, the wireless LAN network 103 matches the condition and is extracted.

  Thereafter, the port and service used by the terminal 101b for communication are extracted by “extract used port and service” (step S1605). The terminal 101b uses the port Pv for moving picture transmission and the port Pa for voice transmission.

  Step S1606 is a process of “outputting a request for switching from the network B to the network C with respect to a port used by the network C better than the network B”. In this process, the network switching process is performed for the port number of the service determined to have a higher priority than the network (network B) that is newly connectable in step S1604 above the network (network B) in communication. . In this embodiment, it is assumed that the mobile network 102 with a wide area is used for voice transmission at the port Pa, and the wireless LAN network 103 with a wide band is used for video transmission. Therefore, the port to be switched is only the port Pv and the switching destination is the wireless LAN network 103.

  In the following, the transmission path switching process of the port Pv will be described in the order of the IMS server search and the switching request process.

  In the IMS server search 1302, the terminal 101b searches for the IMS server and acquires the address IPt of the second IMS server 111. Further, the terminal 101b outputs the SIP registration 1303 of the terminal ID1 to the second IMS server 111. In that case, a SIP Registration message is used.

  The communication process between the second IMS server 111 and the terminal 101b is the same as the IP address acquisition process of the first server in the first IMS server 107. However, in this case, since the mobile network 102 is the home network of the terminal 101, the wireless LAN 103 is a visited network. Therefore, since the S-CSCF in the IMS specification of TS 23.228 is the first IMS server 107, the second IMS server 111 performs the operation of the P-CSCF. First, the IMS server of the second IMS home network is searched using the user ID of the terminal 101b. As a result, the first IMS server 107 and its IP address IPs are searched, and a connection between the second IMS server 111 and the first IMS server 107 is formed.

  At this time, the second IMS server 111 performs processing as follows. When the SIP registration 1303 by the terminal 101a is input, the second IMS server 111 performs SIP registration processing on the second IMS server 111. At this time, in the second IMS server 111, when the GGSN / PDG communication unit 407 first performs IP protocol processing in the IP communication unit 404 up to the MAC layer and the SIP registration 1303 is input, the terminal control unit 401 Parses the message. In this case, since it is SIP registration for the visited network, the terminal control unit 401 passes a request to the transfer control unit 403.

  The transfer control unit 403 performs processing for searching for an IMS server of the home network using the user ID as a key in cooperation with the user information storage device 113 via the IP communication unit 404 and the GGSN / PDG communication unit 407. As a key at this time, IMSI, a domain name extracted from the user ID, a GGSN address, or a GGSN number may be used in addition to the user ID.

  When the search is completed, the IP address IPs of the first IMS server 107 is registered in the terminal state management unit 402 together with the user ID of the terminal 101b. Thereafter, a signal from the terminal 101 b is output to the first IMS server 107. The first IMS server 107 registers the terminal 101b and outputs a response to the second IMS server 111, as in the home network. Then, the second IMS server 111 outputs the above response as it is to the terminal 101b. In the terminal 101b, the terminal control unit 501 stores the IP address IPt of the second IMS server 111 in the terminal state management unit 502 as the IMS server IP address 608.

  Thereafter, an IMS-related call control signal is transmitted from the terminal 101b via the wireless LAN network 103 and the second IMS server 111 through a path called the first IMS server 107. This time is “time (b)”, and the data stored in the node at this time is shown in “(b)” in FIGS.

  The terminal 101b changes the stream related to the home IP address IPc related to the video port Pv from the IP address IPa via the mobile network 102 to the IP address IPb via the IP address IPp of the packet data relay device 110 of the wireless LAN network 103. The route change request 1304 to be output is output to the second IMS server 111.

  Inside the terminal 101 b, the terminal call control unit 501 generates a route change request 1304 and outputs it to the wireless LAN network 103. The route change request 1304 includes a terminal ID ID1 of the terminal 101b, a home IP address IPc, a terminal (access) IP address IPa before the change, a terminal (access) IP address IPb after the change, and an IP address of the transfer destination relay device IPp, port number Pv, and terminal ID ID1 are acquired from the terminal state management unit 502 and stored.

  When the path change request 1304 is input, the second IMS server 111 outputs a transfer setting request 1305 specifying a transfer target stream and a transfer destination to the packet data relay apparatus 110. Further, the second IMS server 111 transfers the route change request 1306 as it is to the first IMS server 107.

  A route change request 1304 is input by the GGSN / PDG communication unit 407 inside the second IMS server 111. The terminal control unit 401 analyzes the route change request 1304 detected from the IP communication unit 404 and detects that it is a route change request. The terminal control unit 401 uses the IP communication unit 404 and the IMS communication unit 406 to output a route change request 1304 to the first IMS server 107 having the home server IP address IPs.

  When the path change request 1306 is input from the second IMS server 111, the first IMS server 107 searches the mobile network packet relay apparatus 106 from the terminal ID ID1 or the terminal IP address IPa before the change, and outputs a transfer setting request 1307. . Inside the first IMS server 107, a route change request 1306 is input via the IMS communication unit 406 and the IP communication unit 404. The terminal control unit 401 analyzes the route change request 1306, and determines the terminal IP address IPa before the change, the terminal IP address IPb after the change, the IP address IPp of the transfer destination relay device, the port number Pv, and the terminal ID ID1. Extract.

  Here, since the gateway of the terminal 101 to the public packet network is the mobile network packet relay device 106, the terminal control unit 401 uses the terminal ID ID1 included in the route change request 1306, the terminal IP address IPa before the change, and the transfer destination. A transfer setting request 1307 for requesting a transfer change storing the IP address IPp of the relay device and the port number Pv is generated, and is transmitted to the mobile network packet control device 106 via the IP communication unit and the GGSN / PDG communication unit 407. Output.

  When a signal for requesting transfer change is input in the transfer setting request 1307, the mobile network packet relay device 106 compares the IP address of the transfer destination relay device in the signal with its own IP address. In this case, since the IP address IPp of the transfer destination relay device is different from the IP address IPg of the main relay device 707, the setting of the transfer destination relay device IP address 705 is changed to IPp for the port Pv specified by the signal.

  In the mobile network packet relay device 106, when a transfer setting request 1307 is input to the GGSN connection setting unit 201 via the IMS communication unit 207, the GGSN connection setting unit 201 determines that the terminal state management unit 302 is based on the terminal ID ID1. The internal main relay device IP address 706 is searched. The GGSN connection setting unit 201 adds the used port number Pv and the transfer destination IP address IPp to the terminal state management unit 202 because the designated transfer destination relay device IP address IPp is different from the IPg of the main relay device IP address 706. Then, the GGSN connection setting unit 201 outputs a signal for confirming the transfer change to the first IMS server 107 via the IMS communication unit 207. If the specified forwarding destination relay device IP address and the main relay device IP address 706 are the same and there is an entry related to the port specified by the signal, the entry is deleted.

  When the transfer setting process is completed, the first IMS server 107 outputs a path change confirmation 1308 that is a response to the path change request to the second IMS server 111. The terminal control unit 401 of the first IMS server 107 stores information (eg, a terminal ID or an identifier uniquely assigned to a message) for associating with the route change request 1306, generates a route change confirmation 1308, and performs IP communication. The data is output to the terminal 101b via the unit 404 and the GGSN / PDG communication unit 407.

  When the path change confirmation 1308 is input from the first IMS server 107, the second IMS server 111 performs a transfer change process for receiving and changing the transfer setting 1309 of the packet data relay apparatus 110, which is a relay apparatus of its own network. As a result, the setting of the packet data relay device 110 is changed.

  When the packet data relay apparatus 110 receives the transfer setting 1309 and receives a signal for requesting transfer change in the transfer change process, the packet data relay apparatus 110 compares the IP address of the transfer destination relay apparatus in the signal with its own IP address. In this case, since the IP address IPp of the transfer destination relay device is different from the IP address IPg of the main relay device 807, the setting of the transfer destination relay device IP address 805 is changed to IPp for the port Pv specified by the signal.

  In the mobile network packet relay device 106, when a transfer setting request 1307 is input to the GGSN connection setting unit 201 via the IMS communication unit 207, the GGSN connection setting unit 201 starts from the terminal ID ID 1 in the terminal state management unit 302. The main relay device IP address 806 is searched. Since the designated transfer destination relay device IP address IPp is different from the IPg of the main relay device IP address 806, the GGSN connection setting unit 201 adds the used port number Pv and the transfer destination IP address IPp to the terminal state management unit 202. Then, the GGSN connection setting unit 201 outputs a signal for confirming the transfer change to the first IMS server 107 via the IMS communication unit 207. If the specified forwarding destination relay device IP address and the main relay device IP address 806 are the same and there is an entry related to the port specified by the signal, the entry is deleted.

  When the setting of the packet data relay device 110 is completed, the second IMS server 111 outputs a route change confirmation 1310 to the terminal. The terminal control unit 401 of the second IMS server 111 stores information (for example, an identifier uniquely assigned to a terminal ID or a message) to be associated with the route change request 1304, generates a route change confirmation 1308, and performs IP communication. The data is output to the terminal 101b via the unit 404 and the GGSN / PDG communication unit 407.

  When the processing is completed, the terminal 101b stores a set of the port Pv and the access IP address IPp for the port Pv in the terminal state management unit 502.

  This completes the switching process. Thereafter, in the mobile network packet control device 106 and the packet data relay device 110, the IP packet transfer 1311 related to the voice data and the IP packet transfer 1312 related to the moving image data are performed as follows.

  FIG. 17 is a flowchart for explaining the packet transfer operation of the mobile network packet relay device 106 or the packet data relay device 110 in the present embodiment. Hereinafter, this flow will be described in three cases. .

  The first relates to the packet transfer operation from the terminal 101b to the opposite node 116, and the processing of the mobile network packet relay device 106 corresponds to this. Since the mobile network packet relay device 106 becomes the main relay device of the terminal 101b, it is determined “Yes” in the branch of step S1701 to determine whether it is the home network relay device of the terminal 101b, and the process proceeds to step S1702. In step S1702, it is determined whether or not the transfer source is a home agent. Since the transfer source is the terminal 101b, “Yes” is determined and the process proceeds to step S1703. In step S1703, the transfer destination IP address is set as the IP address of the home agent.

  The second relates to the packet transfer operation from the terminal 101b to the opposite node 116, and the processing of the packet data relay apparatus 110 corresponds to this. The packet data relay device 110 becomes a relay device of the wireless LAN network 103 which is the visited network of the terminal 101b. Therefore, in the branch of step S1701, “No” is determined and the process proceeds to step S1705. In step S1705, it is determined whether or not the transfer source is a home agent. Since the transfer source is the terminal 101b, “Yes” is determined, and the process proceeds to step S1706. In step S1706, the transfer destination IP address is set as the IP address of the main relay device. Note that the transfer destination IP address in this case is IPg which is the IP address of the mobile network packet relay device 106.

  The third is a packet transfer operation from the opposite node 116 to the terminal 101b. In this case, regardless of the position of the terminal, the determination results in steps S1702 and S1705, which are the same / non-identical determinations of the transfer source and the home agent, are both “No”, and the process proceeds to step S1704. In step S1704, the transfer destination IP address is selected from the terminal and the port number. Here, if the port number is Pv, the transfer destination IP address is IPp, and if the port is Pa, the transfer destination IP address is IPg.

  In the terminal 101, either the GPRS communication unit 506 or the WLAN access IP communication unit 508 is used by the IP distribution communication unit 505 to use the used network relay device IP address 610 corresponding to the used port number 09 in the terminal state management unit 502. The communication unit to be used is selected, and the IP packet is transferred to the used network relay device IP address 610.

  After the transfer destination IP address is determined, step S1507 is executed to output the relay target IP packet to the transfer destination IP address. This time is “time (c)”, and the data stored in the node at this time is shown in “(c)” in FIGS.

  The above is the content of the packet transmission branch setting process when a terminal enters the wireless LAN network 103 during communication with the mobile network 102. The embodiment described so far depends on the usage of the system. Needless to say, it can be changed as appropriate.

  For example, when a terminal enters the mobile network 102 during communication with the wireless LAN network 103 as in the case where the terminal enters the wireless LAN network 103 during communication with the mobile network 102, the wireless LAN A mobile network packet relay device in which the IMS server is a control target even when entering another wireless LAN network during communication with the network 103 and when entering another mobile network during communication with the mobile network 102 A similar effect can be realized by controlling the packet data relay apparatus.

  Further, when the branching of the IP packet realized by the present embodiment is canceled, the path change request may be made by storing the access IP address of the home network in the switching destination IP address.

  Furthermore, even when the home agent 115 and the mobile packet relay device 106 or the packet data relay device 110 are integrated, a system similar to the above can be configured. In this case, since the access IP address of the integrated network matches the home IP address, there is no need to establish a tunnel, and the effect of improving transmission efficiency can be obtained.

  In the above-described embodiment, the use of a network that can be connected in a wide band for moving image transmission is used as a network determination criterion. However, a connection destination can also be set based on preference information related to a user's communication line.

  In addition, when the terminal 101 starts communication when the standby process is in progress, the registration process for branching the packet transmission described in the above-described embodiment is performed, and the terminal 101 starts communication, the branch as illustrated in the latter half of the present embodiment. It is also possible to immediately execute the packet transmission.

  When communication is disconnected, the settings of all ports related to the communication can be changed so as not to branch. For this purpose, a route change request in which the IP address of the main relay device is stored as the switching destination address is output to all ports to which the terminal 101 branches when the service is disconnected, or the terminal corresponds to the IMS server. The port used for communication is stored, and when the communication is cut off, a route setting request for releasing all port branches is output from the IMS server to the mobile network packet relay device or packet data relay device.

  When this embodiment is applied to Mobile IPv6, using hierarchical Mobile IPv6, mobile network packet relay apparatus 106 or packet data relay apparatus 110 is set as MAP (Mobility Anchor Point), and these addresses are care-of addresses 1102. It is possible to achieve the same effect as this embodiment by storing in the storage.

  In the above-described embodiment, the processing when the home network and the main relay device match is shown. However, the IMS server has a function of searching for the network to which the main relay device belongs, so that the home network and the main relay device can be searched. Even when the relay devices are different, it is possible to perform the same path switching as in the above-described embodiment. In this case, for example, when the terminal 101 registers Mobile IP, information (the IP address of the IMS server, the IP address of the relay device, the domain name, etc.) and the terminal ID are specified to the IMS server. When the terminal 101 outputs a route change request to the IMS server, the IMS server acquires information for identifying the main relay device from the registered information, and further, IMS that belongs to the same network as the main relay device from the information. The server IP address may be acquired from the user information storage device 113.

  Further, in the above-described embodiment, the route change method for the two networks before and after the change has been described. However, the information specifying the network to which all the relay devices used by the terminal 101 belong to the first IMS server 107 belongs. And the path change request is sent from the first IMS server 107 to the IMS servers of all the networks used by the terminal 101, and all the IMS servers that receive the signal of the second IMS server 111 of the above-described embodiment Similarly to the transfer change process, it is also possible to change the routes for three or more networks by performing the transfer change process of the relay devices belonging to the same network.

  In the above-described embodiment, the path switching is realized by simultaneously changing the settings of the relay apparatuses of a plurality of networks using the IMS server. However, the network relay apparatuses used before and after the path change And an interface for transmitting / receiving a route change request and a section for retrieving the IP address of the relay device of the network before the change from the network after the change, and a transfer change process similar to the present embodiment from the network before the change Even if it performs, the effect similar to the above-mentioned embodiment is acquired.

  In addition, an interface for path change is provided between the terminal 101 and the relay device, and all the relay devices in the connectable network have access IP addresses before and after the change, IP addresses of the transfer destination relay devices after the change, The same effect as described above can be obtained by outputting a route change request including the IP address of the main relay device from the terminal to the relay device and making the same change as in the above-described embodiment according to the request. .

  In this embodiment, the first relay device accessed after the terminal is turned on becomes the main relay device, but the main relay device can be changed by appropriately rewriting the contents of the terminal state management unit of each device. It is. In this case, the main relay device can be selected by the user or the network based on the distance and positional relationship with the terminal, and the bandwidth, delay, and throughput of the main relay device and other relay devices or the radio access network can be reduced. Based on this, a method of changing the connection destination to a network capable of communication most suitable for the application is also conceivable.

  As described above, in the present embodiment, the IMS server is provided with the terminal state management unit 402 and the transfer setting unit 403, and the IMS server of the transfer destination network sends the transfer setting request to the IMS server of the transfer source network. Output, and both the transfer source and transfer destination network relay devices store the IP addresses of the terminals in the transfer source and transfer destination networks in the terminal state management unit, and the packet relay unit 204 of the mobile network packet relay device 106 and the packet The packet relay unit 304 of the data relay device 110 and the IP distribution communication unit 505 of the terminal 101 specify the network of the packet data transmission destination for each port, and the communication quality can be improved without causing the home agent 116 to modify the existing home agent. The effect which cannot be obtained by the conventional system of improving is acquired.

  In addition, by providing an IMS server that outputs a route change request from the terminal 101 to the IMS server and changes the transfer setting of the relay device according to the route request, the user designates settings and operations of the terminal 101. The effect that the transmission path of packet data can be flexibly changed is obtained.

  Furthermore, by providing the IMS server with a terminal control unit 401 that controls the relay device from the IMS server, even if the information about the mutual address is not stored between the source and destination relay devices, the transmission path for each port. The effect that can be switched is obtained.

(Second Embodiment)
The system configuration of the interwork system according to the present embodiment is the same as that of the first embodiment described above. Therefore, the block diagram showing the system configuration of the interworking system of the present embodiment, the block diagram showing the internal configuration of the mobile network packet relay device, and the block diagram showing the internal configuration of the packet data relay device are also already referenced. 1, 2 and 3 are used. In the following, the operation continued from the final state of the operation of the system described in the first embodiment will be described.

  FIG. 18 is a sequence diagram showing the operation of the system according to the second embodiment of the present invention. In this sequence diagram, the operation continued from the final state of the operation of the system described in the first embodiment is shown. It is shown.

  The mobile network packet relay device 106 exchanges operation information such as traffic volume, number of connections, CPU usage rate, line usage rate, etc. handled by both relay devices at regular intervals with the packet data relay device 110 as an operation status exchange 1801. To do. The exchange of the operation state exchange 1801 may be performed when there are terminals that can access both the mobile network packet relay apparatus 106 and the packet data relay apparatus 110 at the same time.

  In the mobile network packet relay device 106, the GGSN connection setting unit 201 measures the state of the mobile network packet relay device 106 and outputs it to the packet data relay device 110 via the PDG / PDN communication unit 206. On the other hand, the operation information input from the packet data relay apparatus 110 is input to the PDG state management unit 203 via the PDG / PDN communication unit 206.

  In the packet data relay device 110, the PDG connection setting unit 301 measures the state of the packet data relay device 110 and outputs it to the mobile network packet relay device 106 via the GGSN / PDN communication unit 306. On the other hand, the operation information input from the mobile network packet relay device 106 is input to the SSGN state management unit 303 via the GGSN / PDN communication unit 306.

  In the packet data relay apparatus 110, “switch determination” (step S1802) is based on the operation information acquired in the operation state exchange 1801, and the PDG connection setting unit 301 acquires information from the GGSN state management unit 303 while checking the load level. The degree of congestion is determined, and switching determination processing is performed.

  The determination based on the operation information in the mobile network packet relay apparatus 106 is performed by the GGSN connection setting unit 201 acquiring information of the PDG state management unit 203. The mobile network packet relay device 106 determines the degree of load or the degree of congestion from the operation information of the mobile network packet relay device 106 and the packet data relay device 110.

  When the packet data relay apparatus 110 determines to switch, the packet data relay apparatus 110 outputs a MIP route change request 1803 to the home agent 115.

  Inside the packet data relay device 110, the PDG connection setting unit 301 extracts all the terminal ID, home IP address, and access IP address of the terminal using the home agent 115 from the terminal state management unit 302. For all these sets of data and each set, the IP address IPp of the packet data relay device 110 that is the output source of the request is stored in the main relay device IP address 706 (see FIG. 7). Also, an MIP route change request 1803 is generated that is the care-of address of all the terminals from which the IP address IPp of the packet data relay device 110 is extracted, and is output to the home agent 115. Thereafter, the packet is relayed according to the flow of FIG. 17 referred to in the first embodiment.

  Further, the packet data relay apparatus 110 changes the main relay apparatus 1804 to instruct “change main relay apparatus” to change the main relay apparatus of all terminals stored in the MIP route change request 1803 to the IP address IPp of the packet data relay apparatus 110. Is output to the mobile network packet relay device 106.

  In the mobile network packet relay device 106, when the terminal control unit 201 detects the main relay device change 1804 instructing “change main relay device”, the main relay device IP address 706 for all the terminal IDs included in the change is transmitted from IPg. Rewrite to IPp. When the processing is completed, the mobile network packet relay device 106 outputs a response indicating completion to the packet data relay device 110.

  When the MIP route change request 1803 is input, the home agent 115 rewrites the care-of address entries corresponding to all the corresponding terminals to the IP address IPp of the packet data relay device 110, and further the packet of the terminal corresponding to the rewritten entry. Change the transmission path.

  When the processing is completed, the home agent 115 outputs a route change confirmation 1805 to the packet data relay device 110.

  The audio data path changed as a result of the above processing is shown as 1806 (Audio), and the moving picture data path is shown as 1807 (Video). The time of this change is “time (d)”, and the data stored in the node at this time is shown in “(d)” of FIGS.

  In addition, in the main relay device change 1804 of the “main relay device change” process for the mobile network packet relay device 106, the timing for changing the main relay device is specified to synchronize with the main relay device change timing of the packet data relay device 110. In addition to obtaining the same effect, the timing for changing the value between the mobile network packet relay device 106 and the packet data relay device 110 is shifted so that the IP packet is between the two. It is possible to avoid the inconvenient phenomenon of going back and forth and being discarded.

  In this embodiment, switching is realized by signal transmission / reception between the mobile network packet relay device 106 and the packet data relay device 110 on the network side, but instead of the MIP registration change request from the packet data relay device 110. Then, a notification for instructing or recommending a change of the main relay device (change of the care-of address) is given to a terminal that is a candidate for changing the main relay device. Furthermore, even if the terminal outputs a request for switching the care-of address to the home agent 115 according to the notification, the same effect can be obtained, and the user can determine whether or not the change can be made. An interface between the mobile network packet relay device 106 and the packet data relay device 110 is not required, and the use of existing devices is facilitated.

  In the above-described embodiment, the method of switching all the terminals belonging to the main relay apparatus to be switched at a time has been described. However, the number of terminals to be switched is reduced depending on the state of the terminal, the service being used, and the necessary QoS parameters. It is also possible to do.

  As described above, in the present embodiment, the mobile network packet relay device 106 including the GGSN connection setting unit 201 that notifies the operation state of the mobile network packet relay device 106 and changes the main relay device, and the state of the packet data relay device 110 And the packet data relay device 110 including the PDG connection setting unit 301 that changes the main relay device, thereby switching traffic with the home agent 115 and avoiding an increase in network load and congestion. The effect that it becomes possible is acquired.

  Although the presently preferred embodiments of the present invention have been described above, it will be understood that various modifications can be made to the present embodiments and are within the true spirit and scope of the present invention. It is intended that the claims include all such variations.

  The wireless communication system according to the present invention has a function of allowing a user to select a communication network to be used according to the type and characteristics of transmission data, and is useful as a cooperative system using a plurality of communication networks. Further, the present invention can also be applied to uses such as failure avoidance for avoiding a situation where a communication carrier concentrates loads on some networks and nodes or congestion occurs.

FIG. 1 is a block diagram showing a system configuration of an interworking system according to the first embodiment of the present invention. FIG. 2 is a block diagram showing an internal configuration of the mobile network packet relay device according to the first embodiment of the present invention. FIG. 3 is a block diagram showing an internal configuration of the packet data relay device according to the first embodiment of the present invention. FIG. 4 is a block diagram showing an internal configuration of the IMS server according to the first embodiment of this invention. FIG. 5 is a block diagram showing the internal configuration of the terminal according to the first embodiment of the present invention. FIG. 6 is a field diagram showing data of the terminal state management unit of the terminal according to the first embodiment of the present invention. FIG. 7 is a field diagram showing data of the terminal state management unit of the mobile network packet relay device according to the first embodiment of the present invention. FIG. 8 is a field diagram showing data of the terminal state management unit of the packet data relay device according to the first embodiment of the present invention. FIG. 9 is a field diagram showing data of the terminal state management unit of the first IMS server in the first embodiment of the invention. FIG. 10 is a field diagram showing data of the terminal state management unit of the second IMS server according to the first embodiment of this invention. FIG. 11 is a field diagram showing data of the terminal state management unit of the home agent according to the first embodiment of the present invention. FIG. 12 is a sequence diagram when the terminal is located in the cell M1 in the first embodiment of the present invention. FIG. 13 is a sequence diagram when the terminal moves to the cell L1 in the first embodiment of the present invention. FIG. 14 is a terminal state transition diagram according to the first embodiment of the present invention. FIG. 15 is a flowchart for explaining the operation of the terminal at the time of location registration according to the first embodiment of the present invention. FIG. 16 is a flowchart for explaining the operation of the terminal during communication according to the first embodiment of the present invention. FIG. 17 is a flowchart for explaining the packet transfer operation of the mobile network packet relay device or the packet data relay device according to the first embodiment of the present invention. FIG. 18 is a sequence diagram showing the operation of the system according to the second embodiment of the present invention. FIG. 19 is a diagram for explaining an outline of a system configuration in which Mobile IPv6 and 3GPP interworking systems are combined. FIG. 20 is a conceptual diagram for explaining the method disclosed in Japanese Patent Application Laid-Open No. 2004-180311.

Claims (8)

A wireless communication system,
A public packet network, a plurality of wireless communication networks each provided with a relay device, a terminal capable of packet connection with the plurality of wireless communication networks, and an opposite node that performs packet communication with the terminal via the public packet network And a router that manages the destination of the terminal that changes according to the movement of the terminal,
The terminal designates a relay device that relays a packet transmitted from the opposite node to the terminal for each port number of the terminal, and designates the relay device as a main relay device selected from the plurality of relay devices. Set the information to be
The router outputs a packet addressed to the terminal input from the opposite node to the main relay device,
The main relay device outputs a packet addressed to the terminal to a relay device that is a transfer destination of an IP address designated for each port number of the terminal,
The relay device outputs a packet addressed to the terminal input from the main relay device to the terminal;
The wireless communication system, wherein the terminal outputs a packet addressed to the opposite node to a transfer destination relay device having an IP address designated for each port number. The wireless communication system according to claim 1, wherein
A main network IMS server that performs packet call call control belonging to a radio communication network of the main network provided with the main relay device, and performs packet call call control for each radio communication network in the area other than the main network. A visited network IMS server to execute,
The visited network IMS server executes a transfer setting process for relaying a packet having a designated port number to a relay device provided in the visited network, and the identifier of the terminal, the port number, A route change request storing the set of IP addresses of the forwarding destination relay devices is output to the main network IMS server;
The main network IMS server is configured to execute a transfer setting process for changing the transfer destination of a packet having a designated port number to the transfer destination relay device in response to the route change request to the main relay device. Wireless communication system. The wireless communication system according to claim 2,
The terminal is configured to output the route change request to the main network IMS server or the visited network IMS server;
The visited network IMS server is a wireless communication system configured to execute the transfer setting process in response to a route change request from the terminal. The wireless communication system according to claim 2,
Relay device setting unit for outputting operation information of one relay device selected from among the plurality of relay devices, and operation information management for collecting operation information output from other relay devices other than the one relay device With
The one relay device compares the operation information of the one relay device with the operation information of the other relay device, and performs a main relay device change process for switching the main relay device based on the result. To the relay device of
The other relay device executes a change process in which the main relay device corresponding to the terminal designated based on the main relay device change process is the one relay device,
The one relay device is configured to output, to the router, a MIP route change request for registering the address of the one relay device as a care-of address with the change of the main relay device. . Provided in each of the public packet network, a plurality of wireless communication networks, a terminal capable of packet connection with the plurality of wireless communication networks, an opposite node that performs packet communication with the terminals, and the plurality of wireless communication networks A wireless communication method in a system comprising: a relay device connected to the opposite node via the public packet network; and a router that manages a destination of the terminal that changes according to movement of the terminal,
The terminal specifies, for each port number of the terminal, a relay device that relays a packet transmitted from the opposite node to the terminal, and selects information specifying the relay device from the plurality of relay devices. A step for setting to the main relay device,
The router outputting a packet addressed to the terminal input from the opposite node to a main relay apparatus selected according to the terminal from the relay apparatus;
The main relay device outputting a packet addressed to the terminal to an IP address of a forwarding relay device designated for each port number of the terminal;
The relay device outputting a packet addressed to the terminal input from the main relay device to the terminal;
And a step in which the terminal outputs a packet addressed to the opposite node to an IP address of a forwarding destination relay device designated for each port number. The wireless communication method according to claim 5, wherein
A visited network IMS server that performs call control of a packet call for each visited network that does not belong to the wireless communication network of the main network in which the main relay device is provided, to the relay device provided in the visited network, The main relay device executes a transfer setting process for relaying the packet of the designated port number, and the route change request storing the set of the terminal identifier, the port number, and the IP address of the forwarding destination relay device is received by the main relay device Outputting to a main network IMS server that performs call control of packet calls belonging to a wireless communication network of the provided main network;
The main network IMS server, in response to the path change request, executing a transfer setting process for changing the transfer destination of a packet having a specified port number to the transfer destination relay device, to the main relay device; A wireless communication method comprising: The wireless communication method according to claim 5, wherein
The terminal outputting the route change request to the main network IMS server or the visited network IMS server;
The visited network IMS server executing the transfer setting process in response to a route change request from the terminal. The wireless communication method according to claim 5, wherein
One relay device selected from the plurality of relay devices compares the operation information of the one relay device with the operation information of other relay devices other than the one relay device, and based on the result, Executing a main relay device change process for switching the main relay device on the other relay device;
The other relay device changing a main relay device corresponding to the terminal designated based on the main relay device change process to the one relay device;
A step in which the one relay device outputs a MIP route change request for registering the address of the one relay device as a care-of address with the change of the main relay device to the router. Method.

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